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TV detector van

151 points by rishabhd 7y ago

saagarjha 7y ago
How do these work? Is a TV somehow different than a large monitor?
- DanBC 7y ago
  No, a tv isn't that much different from a large monitor. In the past when we had CRTs and poor EMF shielding TV detector vans claimed to use "van eck phreaking" https://en.wikipedia.org/wiki/Van_Eck_phreaking https://en.wikipedia.org/wiki/Van_Eck_phreaking. They had a couple of actual working vans, but these were purely for technical demonstrations. The rest of the vans were labelled up and they'd drive around to places that didn't have a licence (For a while TV Licencing had the largest civilian database in the UK) and knock on doors. Some of the "inspectors" used, and still use, pretty unpleasant techniques. I'm generally in favour of the licence. I don't need one right now, and I've found it easy to get the letters to stop (I fill out an online form), but some friends get letters almost fortnightly. They have mental ill-health, and they find the letters distressing. It's annoying to me that TVL / Capita aren't better at supressing those letters.
- ungzd 7y ago
  > The most common suggested method was the detection of a signal from the TV's local oscillator. See: superheterodyne receiver. Most modern radio receivers generate high-frequency signal for tuning, which leaks as radio signal (receiver becomes in some way a transmitter). However, it's not confirmed if these vans had working detectors, or were just for intimidation. There were also stories about: - Radar detector detectors (in places where radar detection devices in cars were illegal) - Broadcast radio receivers detectors installed near roads to measure popularity of radio stations among drivers
- NikkiA 7y ago
  You look for the IF from the tuner, almost all tuners are made using the exact same frequency building blocks, and thus the tuner can easily be detected and knowing which channel it is tuned to. There's a reason all the BBC channels are on the same DTV mux with ITV & others on different muxes - it means the BBC channels that require a license are all on the same tuner frequency for a local area.
- id10t-detector 7y ago
  Tv is a monitor with a tuner.
octosphere 7y ago
Such an archaic thing to have when the masses have largely adopted smartphone and tablets and are subscribers of things like NowTV, Netflix, Amazon Prime Video, or even paid YouTube subscriptions (among other less popular services which I am leaving out).
- notyourwork 7y ago
  I doubt cable companies would invest in such things if they weren't finding consumers abusing their services. We are not in a point where cable subscriptions are a minority so I think depending on demographic your argument is valid but for total population there are lots still paying for and watching cable.
tlb 7y ago
"...it was thought that they operated by detecting electromagnetic radiation given off by a TV. The most common suggested method was the detection of a signal from the TV's local oscillator." This seems extremely tricky to do, and it wouldn't be very directional. Why not just look for the flickering light pattern from a TV coming out people's windows? You could correlate the brightness changes with the broadcast signals on each channel to know what people are watching.
- woodrowbarlow 7y ago
  that's exactly how it works, apparently: "the optical detector in the detector van uses a large lens to collect that light and focus it on to an especially sensitive device, which converts fluctuating light signals into electrical signals, which can be electronically analysed"
hprotagonist 7y ago
“Ministry of oooowsinge?” “it was spelt like that on ‘t van!” “what van?” “the cat detector van.” “you are a loony. “
- gumby 7y ago
  My immediate thought too! I'm glad someone else got the reference.
  - mshobe 7y ago
    I am so relieved to find this specific thread.
  - hprotagonist 7y ago
    “i’m raising polecats for peace!”
agurk 7y ago
I lived in a flat in England in the early 2000s which kept getting letters from the BBC saying we didn't have a TV licence. The letters were sometimes more threatening for a period, then sometimes more reconciliatory. They were also running TV adverts at the time claiming they had detector vans about, and if you didn't have a licence you'd be caught. I did some research at the time, and it seemed that evidence from a detector van had never been submitted as evidence in court cases for those without a licence. It didn't take long to realise in the age of databases, it's easier just to send out scary letters to all address without a registered licence and hope there will be some 'conversion rate'. The effort required to actually chase on this seemed disproportional to the benefits. And for those wondering, I did have a licence, it's just the address the BBC had for the flat was subtly different to the one on the bit of paper. I had hoped that they would follow up with a more detailed investigation, so I could see how it worked and ask about the vans, but they never did.
- tantalor 7y ago
  > evidence from a detector van had never been submitted How could it be, if the mechanism behind the detector is not made public? Prosecutor: This machine says you are guilty. Defendant: How does that machine work? Prosecutor: You aren't allowed to know. Defendant: ??? Judge: Case dismissed.
  - stronglikedan 7y ago
    Not the US.
    - rolph 7y ago
      yup even brushing your teeth and using mouthwash is not a stymie, often this is viewed as destruction/interference with evidence, if a cop can discover empty aloholic containers.
      - PhasmaFelis 7y ago
        Brushing your teeth doesn't affect breathalyzer readings at all. Alcoholic mouthwash can give false positives for up to 20 minutes, and cops are supposed to wait and try again for that reason; you've got a good shot at getting it thrown out if they don't.
wyldfire 7y ago
While reading I thought, "for sure we will get to the part of the article where the British realized their folly and discontinued the licensing." But that part never came. Brits: is this for real, does this still exist? Do you pay a license to use your TV? Is it only for OTA programming or using the device in general?
- oxidising 7y ago
  We pay the licence fee to fund the BBC. They make some amazing documentaries (Planet Earth, Blue Planet etc). They also have radio stations, all advert free. Being advert free is rare these days.
  - rtkwe 7y ago
    That's fine, a well funded public broadcaster is a great idea. The question is why in the world is it done as a license fee instead of as a much simpler to implement tax or a subscription where the OTA broadcasts are encrypted and a fee is paid to maintain the ability to decrypt.
    - deleted 7y ago
      [deleted]
    - usrusr 7y ago
      A similar system in Germany (where we are constantly amazed at how much better content the BBC produces) is not a tax to minimize government influence. The goal is to make it public, but not government controlled. Personally I think that it should be organized like a tax nonetheless, because if a public broadcaster is a benefit to society, it's a benefit to those who watch just as much as to those who don't watch, similar to how those who don't enter medical school will still enjoy the availability of doctors. A precedence exists, in Germany the Finanzamt is happily collecting a tax-like thing on behalf of the established churches from their members, without that ever having led anyone to suggest that the churches were controlled by the government. The investure controversy isn't exactly still lingering.
djmobley 7y ago
Watching television without a licence in the UK is actually a criminal (rather than civil) offence, and hundreds of thousands of purple are convicted each year of the offence. https://www.theguardian.com/society/2014/sep/24/in-court-non-payment-tv-licence-television-desperate-cases https://www.theguardian.com/society/2014/sep/24/in-court-non...
- _-___________-_ 7y ago
  To be clear, this only applies to television that is paid for by the license (BBC etc, including streaming via iPlayer). I have a television and use it only to watch Netflix and Amazon Prime Video, and am thus not required to pay the license. Which goes to show how ridiculous these vans are, since they can't tell where you're getting the content you're watching.
  - fourthark 7y ago
    Sounded like they do have technology to tell what content you are watching, which is even more ridiculous.
    - al2o3cr 7y ago
      It would've been borderline-possible in the days of over-the-air television - the first local oscillator in the TV is going to be tuned to a frequency directly related to the channel being watched, so RF leakage would make the channel detectable.
      - lilyball 7y ago
        If you can get any light fluctuation reading at all from the room, you could correlate that with the live channel broadcast and get a match.
    - _-___________-_ 7y ago
      Which content you’re watching isn’t actually relevant, it’s where you are getting the content from. I could be watching a programme via an on-demand service at the same time as it’s shown on live TV, and I still wouldn’t need a license.
aarong11 7y ago
In response a BBC spokeswoman rejected claims that the vans are a hoax: "Detector vans are an important part of our enforcement of the licence fee. We don't go into detail about how many there are or how they work as this information might be useful to people trying to evade the fee." AKA they do nothing other than scare people who wouldn't otherwise pay the license fee into paying it.
- toby- 7y ago
  AKA nothing. As the article mentions, a warrant goes into detail about how the vans function: https://www.whatdotheyknow.com/request/statements_involving_tv_detector https://www.whatdotheyknow.com/request/statements_involving_... The idea they're empty and "just to scare people" is a myth. They are functioning devices.
ropiwqefjnpoa 7y ago
Now that's just silly.
noodlesUK 7y ago
This is such nonsense. In my opinion the BBC should be paid for by a proper tax, as an informed public benefits everyone, or they should just give up on calling it a license. The people going around houses just send threatening letters, and act as though they have some right to enter your home and inspect it (they don't). They go around terrorising people who don't know their rights, but don't watch TV anyway. I routinely get threatening letters from them despite not having a TV on the premises.
- excalibur 7y ago
  The British government has a legal obligation to conduct all business in the least sensible manner available. It's in the Magna Carta.
  - lordnacho 7y ago
    In fact the system of government is derived from strange ladies lying in lakes distributing swords.
    - switch007 7y ago
      If I went around saying I was an emperor just because some moistened bint had lobbed a scimitar at me, they'd put me away!
    - celeritascelery 7y ago
      Given that the parent posters user name is Excalibur, I think they are okay with that.
- pstuart 7y ago
  Then there’s the issue of the cost to enforce licensing.
- groundlogic 7y ago
  Swedish public service transitioned from a per-household fee (for households that held devices capable of showing RF broadcast TV) to a per citizen tax January 1st this year. Of course, they go to great lengths to avoid calling it a tax, but... well, it is a tax. I don't really like it. There's no opt-out any longer. And the content is predictably all-consuming leftist.
BiscoBro 7y ago
God I love the USA.
dsr_ 7y ago
The warrant revealed that a BBC contractor had used an "optical detector" to reveal the possible presence of a TV.[10] The warrant stated that: "the optical detector in the detector van uses a large lens to collect that light and focus it on to an especially sensitive device, which converts fluctuating light signals into electrical signals, which can be electronically analysed. If a receiver is being used to watch broadcast programmes then a positive reading is returned." [10] The BBC stated that this was strong evidence that a set was "receiving a possible broadcast". According to The Comptroller and Auditor General of the National Audit Office, "where the BBC still suspects that an occupier is watching live television but not paying for a licence, it can send a detection van to check whether this is the case. TVL detection vans can identify viewing on a non‐TV device in the same way that they can detect viewing on a television set. BBC staff were able to demonstrate this to my staff in controlled conditions sufficient for us to be confident that they could detect viewing on a range of non‐TV devices." --- That device description is entirely consistent with a video camera, perhaps with a telescope in front of it, used for peering through people's windows. Does this put the BBC at risk of violating anti-peeping-Tom legislation?
- joezydeco 7y ago
  I would think the stray light from a CRT strobing at 50Hz could be picked up by a photodiode and some amplification. The point of the 'detection' was to just see if a TV was in operation and not to see what was being watched.
  - marshray 7y ago
    Ever seen the flickering light of a television behind someone's curtains? Ever seen an app that can identify what song is playing?
  - tantalor 7y ago
    Too many false positives: recorded videos, video games, computers
    - amaccuish 7y ago
sb057 7y ago
Relevant: http://bbctvlicence.com/ http://bbctvlicence.com/
- rwmj 7y ago
  Very relevant. To be honest I'm surprised that TV licensing haven't worked out how this fellow is and added a special exception so he doesn't receive their silly letters.
rtkwe 7y ago
The interesting thing is the Operation section sounds a lot like they're using the same principal behind TEMPEST [0] and van Eck phreaking where leaked emanations from electronic devices can be used to spy on the computation being done and data being displayed. Flat panel displays can be spyed on using this method [1] so it's not completely out of bound of reality that these vans could work as detectors. [0] https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename) [1] https://www.cl.cam.ac.uk/~mgk25/pet2004-fpd.pdf https://www.cl.cam.ac.uk/~mgk25/pet2004-fpd.pdf
- bcaa7f3a8bbc 7y ago
  It's very likely that those vans were used in the 1970s to capture the RF leakage from the local oscillator and other driving circuitry of the CRT TVs. But while it's still technically possible to detect RF leakage from modern LCD TVs, I'm not sure BBC has the capabilities to deploy those and achieve reliable detection. Many people would say these vans became hoaxes at some point in history.
  - rtkwe 7y ago
    Maybe, it would be easier to detect the presence though than to read the actual contents being displayed in theory though.
tomxor 7y ago
You might think these vans were crazy then, what's more crazy today is how they continue to force their opt-out licensing upon everyone like it's still 1946 and they are the only broadcasters in town. If you live in the UK and own a TV you must pay the BBC whether you want the BBC or not! I'm one of the minority who don't own a TV in the UK and even then they make it their business to inform me every two years about all the different ways they can invade my home, fine me extortionate sums and send me to prison for the crime of being caught owning television signal receiving equipment without paying them. Given how nasty all the smart TVs are these days, when I eventually want such luxuries I plan to eventually get a huge monitor and just play netflix or whatever on it... it would be interesting to see their response to that.
- djmobley 7y ago
  To be clear, a licence is required to watch live TV on any channel, not just the BBC.
  - tomxor 7y ago
    I wonder how they define "live TV"? If i watch a live video stream over the internet does it count? I suspect they basically mean the reception of any terrestrial RF TV signal not really caring about it being live, but due to not wanting to go to the trouble of differentiating between BBC and freeview?
    - stordoff 7y ago
      It would count - the definition is deliberately broad ("by any means"): > In this regulation, any reference to receiving a television programme service includes a reference to receiving by any means any programme included in that service, where that programme is received at the same time (or virtually the same time) as it is received by members of the public by virtue of its being broadcast or distributed as part of that service. http://www.legislation.gov.uk/uksi/2004/692/regulation/9/made http://www.legislation.gov.uk/uksi/2004/692/regulation/9/mad...
  - LandR 7y ago
jdofaz 7y ago
On the upside BBC viewers don't have to fast forward through pledge drives like on PBS. This topic reminds me of when The Simpsons had Betty White and PBS pledge enforcement chase down Homer for not paying his pledge.
tehlike 7y ago
Another way this could be possible is embedding inaudible-to-human-ears audio cues into the stream.
- tom_mellior 7y ago
  There was a story going around a while back that claimed that one of the big Silicon Valley companies was doing this: Bought TV ads that had such audio clues, then eavesdropped on you to detect them. I don't recall if it was Facebook's mobile app or Alexa that supposedly did the listening. A very quick web search didn't uncover anything concrete, but I'm somewhat certain I didn't dream this.
  - tehlike 7y ago
    You didnt. It is a real thing. Solid way to do tv ads conversion tracking.
petercooper 7y ago
Have to laugh at all the Americans saying this is crazy or nonsensical when it's legal to carry guns in much of your country :-D That aside, lest anyone think TV detector vans are all over the place, in my almost 40 years of living in the UK I've never seen or had interactions with one. They may as well be the Loch Ness monster for how mythical they are.
- corndoge 7y ago
  > Have to laugh at all the Americans saying this is crazy or nonsensical when it's legal to carry guns in much of your country :-D Not making the connection here, care to elaborate?
  - deleted 7y ago
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  - jdietrich 7y ago
    The TV license is an admittedly odd way of funding a state broadcaster, but it works well enough that nobody has bothered to change it. One mass shooting on the scale of El Paso was enough to prompt a systematic overhaul of British firearms legislation; we just can't understand how so many American citizens can comfortably reconcile your extraordinarily high rate of gun violence with your exceptionally lax gun regulations. https://en.wikipedia.org/wiki/Firearms_(Amendment)_Act_1988 https://en.wikipedia.org/wiki/Firearms_(Amendment)_Act_1988
    - deleted 7y ago
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    - petercooper 7y ago
      "The TV license is an admittedly odd way of funding a state broadcaster, but it works well enough that nobody has bothered to change it." I think the concept of the license is rather alien to people in countries where all civic amenities are subject to the whims of democracy and the government. This is very much not true of many things in the UK (the BBC, the Army, numerous universities and schools, guilds and societies) which would formally exist even if the government were to disappear. I know you probably know all this, so this is really for everyone else's benefit.. but the BBC's entire basis is defined by a Royal Charter which is independent of politics. If the government of the day (or, say, a Trump-esque character) hates the BBC, they can't suddenly defund or destroy it. This is why we do not pay for it in a tax (which the government could adjust) but via a license defined by Royal Charter. I think the British way of having government merely being one more institution amongst many (rather than the institution) is a rather powerful advantage.
rolph 7y ago
we are looking at an iceberg there is more to it: https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename) i know this is about optical side channeling, and tempest is a US effort, but there is a method that was developed and when you can tune in to the synching signal of a TV, CRT, or even an LCD, you can translate the reflected light and reveal much more than presence of a device, You Can Actually Watch what The Suspect Is Watching! A suffieciently motivated attacker with easily fabbed equipment and patience of a ham radio Dx er kinda guy, will know a lot more than presence and use of a "TV" display
djsumdog 7y ago
This kinda makes me thing back to scrambled channels and how companies detected the use of illegal decoder boxes. A lot of them used equipment could detect the demodulation used by a decode and checked to see if you were paying the fee. An easy way around it was just using two VCRs, one before the decode and one after, to stabilize the RF signal.
- aidenn0 7y ago
  I remember a satelite TV company put a message to call a particular number, and then filtered out the message in their official smart cards. Everyone who called the number was pirating their signal.
  - sokoloff 7y ago
    Satellite TV company arranges to "brick" pirate cards across the US days before the Superbowl: https://www.latimes.com/archives/la-xpm-2001-jan-27-mn-17728-story.html https://www.latimes.com/archives/la-xpm-2001-jan-27-mn-17728... https://blog.codinghorror.com/revisiting-the-black-sunday-hack/ https://blog.codinghorror.com/revisiting-the-black-sunday-ha...
    - djsumdog 7y ago
      huh .. but the Superbowl is always on a broadcast network too, so people could always just get out the ole rabbit ears (unless they had really bad signal from their local state)
      - aidenn0 7y ago
        Satellite is most popular where cable does not exist which also tends to be the places with access to the fewest networks.
    - ascagnel_ 7y ago
      It was a genius counter-hack -- distributing the countermeasure piecemeal, in undetectably small pieces, over time, and then building it into the fatal payload before pirates could analyze or block the change. > Several weeks ago, DirecTV began transmitting to its receivers, via satellite, small pieces of the programming code that ultimately killed the altered cards, according to company sources and accounts published on HackHU.com, a Web site devoted to the satellite TV hacking community. The bits of digital information ultimately formed a complete program that--when triggered Sunday--permanently maimed any H card that had been altered. > The result shocked bootleggers, who long had dismissed the steady trickle of software updates as more annoying than serious. When the pirates turned on their television sets Monday, they saw nothing. (The pirates saw the “GAME OVER” message when they studied the software coding that killed their cards, according to HackHU.com and other sites.)
dewey 7y ago
I just spend some time trying to dig up the old TV ads for the licensing fee we had in Austria where they also had some kind of detector van with antennas. Unfortunately I wasn't able to find it. I was always curious how that might work.
- m0xte 7y ago
  AFAIK they detected the emissions from the IF strip on old televisions with a directional yagi antenna mounted on top of the van. This possibility disappeared when the IC based IF sets were developed in the 70s and 80s.
  - dewey 7y ago
    I still remember that van having an antenna like that on top. Might be the case.
trhway 7y ago
interesting that England is the country where they stopped require dog licensing because people would just ignore it. https://en.wikipedia.org/wiki/Dog_licence#United_Kingdom https://en.wikipedia.org/wiki/Dog_licence#United_Kingdom One would think that identifying an unlicensed dog is much simpler than detecting a TV behind the walls.
blunte 7y ago
Reminds me of the cat detector van. http://www.montypython.net/scripts/fishlic.php http://www.montypython.net/scripts/fishlic.php
Emma_Goldman 7y ago
The BBC also claims to be able to detect when anyone uses their online streaming service, IPlayer, though I suspect this may be a ruse to scare people away from watching without a licence. Curiously, the TV licence is a third of the price if you have a black and white television set.
- NeedMoreTea 7y ago
  Not so curious. When the colour licence was introduced, a colour TV was an expensive luxury, and a 12" b&w TV was standard fare for impoverished students. I think the relative differential has increased over the years as students came to rely on the portable telly being the cheap option. At the same time as introducing the colour licence, they abolished the radio licence. btw, as you have to sign in to view iPlayer these days - annoyingly even for radio, I am sure they can detect when people use it. It's not even a bit challenging. :)
boobePhuu7iet7i 7y ago
I never paid for a license. It's insane to be forced to subscribe to a handful of channels you may or may not be interested in. The "inspectors" have no legal right to enter your property, so you can simply tell them to fuck off.
coldtea 7y ago
How about a small flat fee everybody pays to sustain the national broadcaster? Whether they watch it or not is not relevant. It's a nation-wide service at their disposal. Either it's worth it to have, like a dam or a highway system or whatever, and it's ok for people to pay for it in taxes, or it's not, and it should close.
- ktpsns 7y ago
  That's the solution in Germany since a few years. It is called Rundfunkbeitrag and costs 20€ per month per flat.
  - deleted 7y ago
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- yjftsjthsd-h 7y ago
  Because now you're proposing that people be charged for something even if they don't use it and don't want it.
  - coldtea 7y ago
    Yes. In many countries that's how nation-wide infrastructure, services, art programs, and so on are funded. Not on a person per person basis. Not everywhere it's all about the individual and their whims. If the majority (well, through elected representatives) wishes to have and sustain a public good (whether a public broadcaster, or national health service, or arts grants, or whatever), individuals have no other say on the matter. Some countries believe in public goods, and in maintaining through taxes infrastructure to make citizens more educated, informed, cultivated, etc. If someone is a brut and could not care less, they don't get to dictate to the nation not to have those services. E.g. the German example of the tax for the national broadcaster a fellow commenter mentions: "Any household in Germany is legally obliged to pay this quarterly fee, regardless of whether or not you watch the TV channels or listen to the radio stations covered by it. It also covers media consumption online via on-demand services such as media players, streaming services accessed online via computer or smartphone, as well as in-car audio. Shared households are only required to pay this per household, so 4 students living together for example would only be liable for paying the fee once."
JackFr 7y ago
It seems like it would be so much easier to tax the TV's.
LandR 7y ago
I currently have no TV licence. I cancelled it over a year ago as I don't receive a TV signal in my flat. The TV is used for netflix, Amazon Prime, Youtube and the Playstation. I filled out the form to get my refund and you have to choose an option for why you don't need a TV. e.g. you are moving, you are in the military, gone blind or something etc etc. Not an option to tick "I don't watch TV". Anyway, I got the refund and within a week I was getting threatening letters from them saying I don't have a TV licence! Great joined up IT guys. The letters have continued at a rate of one or two a month ever since. I could probably make them stop by calling them, but I already filled out the form, I got my refund... I don't see why I should waste more of time helping them out. I expect at some point someone is going to come to my flat and request to see in the flat to check I'm not watching TV without a licence. If they do they won't be getting let in. It's the tone of the letters that is most annoying, they are quite threatening and they try to be intimidating. I can laugh it off and just bin there nonsense and ignore it, but I could see some people getting upset / intimated into paying, which is sad.
- wlkr 7y ago
  I get these letters regularly. On principle I refuse to deal with Capita/BBC/TVL and would rather they waste the money trying to contact me. There is no obligation to deal with them unless they get a warrant. Only once have they visited and left a calling card but fortunately I was out.
Nas808 7y ago
The entire concept of being charged a fee for broadcast TV, going as far as having enforcers driving around in vans seems very strange to me. But on the other hand, I am very impressed with the quality of programming the BBC puts out.
deleted 7y ago
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jhallenworld 7y ago
The TV license reminds me of the Church Tax that some countries have. This would not fly in the US at all..
zzo38computer 7y ago
I hope somone can figure out how the detection is working, perhaps by making experiments and see what is found to do.
YeGoblynQueenne 7y ago
>> The warrant stated that: "the optical detector in the detector van uses a large lens to collect that light and focus it on to an especially sensitive device, which converts fluctuating light signals into electrical signals, which can be electronically analysed. This "especially sensitive device, which converts fluctuating light signals into electrical signals" sounds remarkably like the human eye. Those signals, of course "can be electronically analysed". Emphasis on "can". Equivalently, "could".
pyman 7y ago
Why drive thousands of vans around the UK, hire contractors and spend tax payers money, when the government can ask Sky and Virgin to provide them with a long list of households that are paying for cable tv (~30 million)? It makes you wonder, doesn't it?

TV detector van

151 points by rishabhd 7y ago

saagarjha 7y ago

How do these work? Is a TV somehow different than a large monitor?

DanBC 7y ago
No, a tv isn't that much different from a large monitor. In the past when we had CRTs and poor EMF shielding TV detector vans claimed to use "van eck phreaking" https://en.wikipedia.org/wiki/Van_Eck_phreaking https://en.wikipedia.org/wiki/Van_Eck_phreaking. They had a couple of actual working vans, but these were purely for technical demonstrations. The rest of the vans were labelled up and they'd drive around to places that didn't have a licence (For a while TV Licencing had the largest civilian database in the UK) and knock on doors. Some of the "inspectors" used, and still use, pretty unpleasant techniques. I'm generally in favour of the licence. I don't need one right now, and I've found it easy to get the letters to stop (I fill out an online form), but some friends get letters almost fortnightly. They have mental ill-health, and they find the letters distressing. It's annoying to me that TVL / Capita aren't better at supressing those letters.
ungzd 7y ago
> The most common suggested method was the detection of a signal from the TV's local oscillator. See: superheterodyne receiver. Most modern radio receivers generate high-frequency signal for tuning, which leaks as radio signal (receiver becomes in some way a transmitter). However, it's not confirmed if these vans had working detectors, or were just for intimidation. There were also stories about: - Radar detector detectors (in places where radar detection devices in cars were illegal) - Broadcast radio receivers detectors installed near roads to measure popularity of radio stations among drivers
NikkiA 7y ago
You look for the IF from the tuner, almost all tuners are made using the exact same frequency building blocks, and thus the tuner can easily be detected and knowing which channel it is tuned to. There's a reason all the BBC channels are on the same DTV mux with ITV & others on different muxes - it means the BBC channels that require a license are all on the same tuner frequency for a local area.
id10t-detector 7y ago
Tv is a monitor with a tuner.

octosphere 7y ago

Such an archaic thing to have when the masses have largely adopted smartphone and tablets and are subscribers of things like NowTV, Netflix, Amazon Prime Video, or even paid YouTube subscriptions (among other less popular services which I am leaving out).

notyourwork 7y ago
I doubt cable companies would invest in such things if they weren't finding consumers abusing their services. We are not in a point where cable subscriptions are a minority so I think depending on demographic your argument is valid but for total population there are lots still paying for and watching cable.

tlb 7y ago

"...it was thought that they operated by detecting electromagnetic radiation given off by a TV. The most common suggested method was the detection of a signal from the TV's local oscillator." This seems extremely tricky to do, and it wouldn't be very directional. Why not just look for the flickering light pattern from a TV coming out people's windows? You could correlate the brightness changes with the broadcast signals on each channel to know what people are watching.

woodrowbarlow 7y ago
that's exactly how it works, apparently: "the optical detector in the detector van uses a large lens to collect that light and focus it on to an especially sensitive device, which converts fluctuating light signals into electrical signals, which can be electronically analysed"

hprotagonist 7y ago

“Ministry of oooowsinge?” “it was spelt like that on ‘t van!” “what van?” “the cat detector van.” “you are a loony. “

gumby 7y ago
My immediate thought too! I'm glad someone else got the reference.
- mshobe 7y ago
  I am so relieved to find this specific thread.
- hprotagonist 7y ago
  “i’m raising polecats for peace!”

agurk 7y ago

I lived in a flat in England in the early 2000s which kept getting letters from the BBC saying we didn't have a TV licence. The letters were sometimes more threatening for a period, then sometimes more reconciliatory. They were also running TV adverts at the time claiming they had detector vans about, and if you didn't have a licence you'd be caught. I did some research at the time, and it seemed that evidence from a detector van had never been submitted as evidence in court cases for those without a licence. It didn't take long to realise in the age of databases, it's easier just to send out scary letters to all address without a registered licence and hope there will be some 'conversion rate'. The effort required to actually chase on this seemed disproportional to the benefits. And for those wondering, I did have a licence, it's just the address the BBC had for the flat was subtly different to the one on the bit of paper. I had hoped that they would follow up with a more detailed investigation, so I could see how it worked and ask about the vans, but they never did.

tantalor 7y ago
> evidence from a detector van had never been submitted How could it be, if the mechanism behind the detector is not made public? Prosecutor: This machine says you are guilty. Defendant: How does that machine work? Prosecutor: You aren't allowed to know. Defendant: ??? Judge: Case dismissed.
- stronglikedan 7y ago
  Not the US.
  - rolph 7y ago
    yup even brushing your teeth and using mouthwash is not a stymie, often this is viewed as destruction/interference with evidence, if a cop can discover empty aloholic containers.
    - PhasmaFelis 7y ago
      Brushing your teeth doesn't affect breathalyzer readings at all. Alcoholic mouthwash can give false positives for up to 20 minutes, and cops are supposed to wait and try again for that reason; you've got a good shot at getting it thrown out if they don't.

wyldfire 7y ago

While reading I thought, "for sure we will get to the part of the article where the British realized their folly and discontinued the licensing." But that part never came. Brits: is this for real, does this still exist? Do you pay a license to use your TV? Is it only for OTA programming or using the device in general?

oxidising 7y ago
We pay the licence fee to fund the BBC. They make some amazing documentaries (Planet Earth, Blue Planet etc). They also have radio stations, all advert free. Being advert free is rare these days.
- rtkwe 7y ago
  That's fine, a well funded public broadcaster is a great idea. The question is why in the world is it done as a license fee instead of as a much simpler to implement tax or a subscription where the OTA broadcasts are encrypted and a fee is paid to maintain the ability to decrypt.
  - deleted 7y ago
    [deleted]
  - usrusr 7y ago
    A similar system in Germany (where we are constantly amazed at how much better content the BBC produces) is not a tax to minimize government influence. The goal is to make it public, but not government controlled. Personally I think that it should be organized like a tax nonetheless, because if a public broadcaster is a benefit to society, it's a benefit to those who watch just as much as to those who don't watch, similar to how those who don't enter medical school will still enjoy the availability of doctors. A precedence exists, in Germany the Finanzamt is happily collecting a tax-like thing on behalf of the established churches from their members, without that ever having led anyone to suggest that the churches were controlled by the government. The investure controversy isn't exactly still lingering.

djmobley 7y ago

Watching television without a licence in the UK is actually a criminal (rather than civil) offence, and hundreds of thousands of purple are convicted each year of the offence. https://www.theguardian.com/society/2014/sep/24/in-court-non-payment-tv-licence-television-desperate-cases https://www.theguardian.com/society/2014/sep/24/in-court-non...

_-___________-_ 7y ago
To be clear, this only applies to television that is paid for by the license (BBC etc, including streaming via iPlayer). I have a television and use it only to watch Netflix and Amazon Prime Video, and am thus not required to pay the license. Which goes to show how ridiculous these vans are, since they can't tell where you're getting the content you're watching.
- fourthark 7y ago
  Sounded like they do have technology to tell what content you are watching, which is even more ridiculous.
  - al2o3cr 7y ago
    It would've been borderline-possible in the days of over-the-air television - the first local oscillator in the TV is going to be tuned to a frequency directly related to the channel being watched, so RF leakage would make the channel detectable.
    - lilyball 7y ago
      If you can get any light fluctuation reading at all from the room, you could correlate that with the live channel broadcast and get a match.
  - _-___________-_ 7y ago
    Which content you’re watching isn’t actually relevant, it’s where you are getting the content from. I could be watching a programme via an on-demand service at the same time as it’s shown on live TV, and I still wouldn’t need a license.

aarong11 7y ago

In response a BBC spokeswoman rejected claims that the vans are a hoax: "Detector vans are an important part of our enforcement of the licence fee. We don't go into detail about how many there are or how they work as this information might be useful to people trying to evade the fee." AKA they do nothing other than scare people who wouldn't otherwise pay the license fee into paying it.

toby- 7y ago
AKA nothing. As the article mentions, a warrant goes into detail about how the vans function: https://www.whatdotheyknow.com/request/statements_involving_tv_detector https://www.whatdotheyknow.com/request/statements_involving_... The idea they're empty and "just to scare people" is a myth. They are functioning devices.

ropiwqefjnpoa 7y ago

Now that's just silly.

noodlesUK 7y ago

This is such nonsense. In my opinion the BBC should be paid for by a proper tax, as an informed public benefits everyone, or they should just give up on calling it a license. The people going around houses just send threatening letters, and act as though they have some right to enter your home and inspect it (they don't). They go around terrorising people who don't know their rights, but don't watch TV anyway. I routinely get threatening letters from them despite not having a TV on the premises.

excalibur 7y ago
The British government has a legal obligation to conduct all business in the least sensible manner available. It's in the Magna Carta.
- lordnacho 7y ago
  In fact the system of government is derived from strange ladies lying in lakes distributing swords.
  - switch007 7y ago
    If I went around saying I was an emperor just because some moistened bint had lobbed a scimitar at me, they'd put me away!
  - celeritascelery 7y ago
    Given that the parent posters user name is Excalibur, I think they are okay with that.
pstuart 7y ago
Then there’s the issue of the cost to enforce licensing.
groundlogic 7y ago
Swedish public service transitioned from a per-household fee (for households that held devices capable of showing RF broadcast TV) to a per citizen tax January 1st this year. Of course, they go to great lengths to avoid calling it a tax, but... well, it is a tax. I don't really like it. There's no opt-out any longer. And the content is predictably all-consuming leftist.

BiscoBro 7y ago

God I love the USA.

dsr_ 7y ago

The warrant revealed that a BBC contractor had used an "optical detector" to reveal the possible presence of a TV.[10] The warrant stated that: "the optical detector in the detector van uses a large lens to collect that light and focus it on to an especially sensitive device, which converts fluctuating light signals into electrical signals, which can be electronically analysed. If a receiver is being used to watch broadcast programmes then a positive reading is returned." [10] The BBC stated that this was strong evidence that a set was "receiving a possible broadcast". According to The Comptroller and Auditor General of the National Audit Office, "where the BBC still suspects that an occupier is watching live television but not paying for a licence, it can send a detection van to check whether this is the case. TVL detection vans can identify viewing on a non‐TV device in the same way that they can detect viewing on a television set. BBC staff were able to demonstrate this to my staff in controlled conditions sufficient for us to be confident that they could detect viewing on a range of non‐TV devices." --- That device description is entirely consistent with a video camera, perhaps with a telescope in front of it, used for peering through people's windows. Does this put the BBC at risk of violating anti-peeping-Tom legislation?

joezydeco 7y ago
I would think the stray light from a CRT strobing at 50Hz could be picked up by a photodiode and some amplification. The point of the 'detection' was to just see if a TV was in operation and not to see what was being watched.
- marshray 7y ago
  Ever seen the flickering light of a television behind someone's curtains? Ever seen an app that can identify what song is playing?
- tantalor 7y ago
  Too many false positives: recorded videos, video games, computers
  - amaccuish 7y ago

sb057 7y ago

Relevant: http://bbctvlicence.com/ http://bbctvlicence.com/

rwmj 7y ago
Very relevant. To be honest I'm surprised that TV licensing haven't worked out how this fellow is and added a special exception so he doesn't receive their silly letters.

rtkwe 7y ago

The interesting thing is the Operation section sounds a lot like they're using the same principal behind TEMPEST [0] and van Eck phreaking where leaked emanations from electronic devices can be used to spy on the computation being done and data being displayed. Flat panel displays can be spyed on using this method [1] so it's not completely out of bound of reality that these vans could work as detectors. [0] https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename) [1] https://www.cl.cam.ac.uk/~mgk25/pet2004-fpd.pdf https://www.cl.cam.ac.uk/~mgk25/pet2004-fpd.pdf

bcaa7f3a8bbc 7y ago
It's very likely that those vans were used in the 1970s to capture the RF leakage from the local oscillator and other driving circuitry of the CRT TVs. But while it's still technically possible to detect RF leakage from modern LCD TVs, I'm not sure BBC has the capabilities to deploy those and achieve reliable detection. Many people would say these vans became hoaxes at some point in history.
- rtkwe 7y ago
  Maybe, it would be easier to detect the presence though than to read the actual contents being displayed in theory though.

tomxor 7y ago

You might think these vans were crazy then, what's more crazy today is how they continue to force their opt-out licensing upon everyone like it's still 1946 and they are the only broadcasters in town. If you live in the UK and own a TV you must pay the BBC whether you want the BBC or not! I'm one of the minority who don't own a TV in the UK and even then they make it their business to inform me every two years about all the different ways they can invade my home, fine me extortionate sums and send me to prison for the crime of being caught owning television signal receiving equipment without paying them. Given how nasty all the smart TVs are these days, when I eventually want such luxuries I plan to eventually get a huge monitor and just play netflix or whatever on it... it would be interesting to see their response to that.

djmobley 7y ago
To be clear, a licence is required to watch live TV on any channel, not just the BBC.
- tomxor 7y ago
  I wonder how they define "live TV"? If i watch a live video stream over the internet does it count? I suspect they basically mean the reception of any terrestrial RF TV signal not really caring about it being live, but due to not wanting to go to the trouble of differentiating between BBC and freeview?
  - stordoff 7y ago
    It would count - the definition is deliberately broad ("by any means"): > In this regulation, any reference to receiving a television programme service includes a reference to receiving by any means any programme included in that service, where that programme is received at the same time (or virtually the same time) as it is received by members of the public by virtue of its being broadcast or distributed as part of that service. http://www.legislation.gov.uk/uksi/2004/692/regulation/9/made http://www.legislation.gov.uk/uksi/2004/692/regulation/9/mad...
- LandR 7y ago

jdofaz 7y ago

On the upside BBC viewers don't have to fast forward through pledge drives like on PBS. This topic reminds me of when The Simpsons had Betty White and PBS pledge enforcement chase down Homer for not paying his pledge.

tehlike 7y ago

Another way this could be possible is embedding inaudible-to-human-ears audio cues into the stream.

tom_mellior 7y ago
There was a story going around a while back that claimed that one of the big Silicon Valley companies was doing this: Bought TV ads that had such audio clues, then eavesdropped on you to detect them. I don't recall if it was Facebook's mobile app or Alexa that supposedly did the listening. A very quick web search didn't uncover anything concrete, but I'm somewhat certain I didn't dream this.
- tehlike 7y ago
  You didnt. It is a real thing. Solid way to do tv ads conversion tracking.

petercooper 7y ago

Have to laugh at all the Americans saying this is crazy or nonsensical when it's legal to carry guns in much of your country :-D That aside, lest anyone think TV detector vans are all over the place, in my almost 40 years of living in the UK I've never seen or had interactions with one. They may as well be the Loch Ness monster for how mythical they are.

corndoge 7y ago
> Have to laugh at all the Americans saying this is crazy or nonsensical when it's legal to carry guns in much of your country :-D Not making the connection here, care to elaborate?
- deleted 7y ago
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- jdietrich 7y ago
  The TV license is an admittedly odd way of funding a state broadcaster, but it works well enough that nobody has bothered to change it. One mass shooting on the scale of El Paso was enough to prompt a systematic overhaul of British firearms legislation; we just can't understand how so many American citizens can comfortably reconcile your extraordinarily high rate of gun violence with your exceptionally lax gun regulations. https://en.wikipedia.org/wiki/Firearms_(Amendment)_Act_1988 https://en.wikipedia.org/wiki/Firearms_(Amendment)_Act_1988
  - deleted 7y ago
    [deleted]
  - petercooper 7y ago
    "The TV license is an admittedly odd way of funding a state broadcaster, but it works well enough that nobody has bothered to change it." I think the concept of the license is rather alien to people in countries where all civic amenities are subject to the whims of democracy and the government. This is very much not true of many things in the UK (the BBC, the Army, numerous universities and schools, guilds and societies) which would formally exist even if the government were to disappear. I know you probably know all this, so this is really for everyone else's benefit.. but the BBC's entire basis is defined by a Royal Charter which is independent of politics. If the government of the day (or, say, a Trump-esque character) hates the BBC, they can't suddenly defund or destroy it. This is why we do not pay for it in a tax (which the government could adjust) but via a license defined by Royal Charter. I think the British way of having government merely being one more institution amongst many (rather than the institution) is a rather powerful advantage.

rolph 7y ago

we are looking at an iceberg there is more to it: https://en.wikipedia.org/wiki/Tempest_(codename) https://en.wikipedia.org/wiki/Tempest_(codename) i know this is about optical side channeling, and tempest is a US effort, but there is a method that was developed and when you can tune in to the synching signal of a TV, CRT, or even an LCD, you can translate the reflected light and reveal much more than presence of a device, You Can Actually Watch what The Suspect Is Watching! A suffieciently motivated attacker with easily fabbed equipment and patience of a ham radio Dx er kinda guy, will know a lot more than presence and use of a "TV" display

djsumdog 7y ago

This kinda makes me thing back to scrambled channels and how companies detected the use of illegal decoder boxes. A lot of them used equipment could detect the demodulation used by a decode and checked to see if you were paying the fee. An easy way around it was just using two VCRs, one before the decode and one after, to stabilize the RF signal.

aidenn0 7y ago
I remember a satelite TV company put a message to call a particular number, and then filtered out the message in their official smart cards. Everyone who called the number was pirating their signal.
- sokoloff 7y ago
  Satellite TV company arranges to "brick" pirate cards across the US days before the Superbowl: https://www.latimes.com/archives/la-xpm-2001-jan-27-mn-17728-story.html https://www.latimes.com/archives/la-xpm-2001-jan-27-mn-17728... https://blog.codinghorror.com/revisiting-the-black-sunday-hack/ https://blog.codinghorror.com/revisiting-the-black-sunday-ha...
  - djsumdog 7y ago
    huh .. but the Superbowl is always on a broadcast network too, so people could always just get out the ole rabbit ears (unless they had really bad signal from their local state)
    - aidenn0 7y ago
      Satellite is most popular where cable does not exist which also tends to be the places with access to the fewest networks.
  - ascagnel_ 7y ago
    It was a genius counter-hack -- distributing the countermeasure piecemeal, in undetectably small pieces, over time, and then building it into the fatal payload before pirates could analyze or block the change. > Several weeks ago, DirecTV began transmitting to its receivers, via satellite, small pieces of the programming code that ultimately killed the altered cards, according to company sources and accounts published on HackHU.com, a Web site devoted to the satellite TV hacking community. The bits of digital information ultimately formed a complete program that--when triggered Sunday--permanently maimed any H card that had been altered. > The result shocked bootleggers, who long had dismissed the steady trickle of software updates as more annoying than serious. When the pirates turned on their television sets Monday, they saw nothing. (The pirates saw the “GAME OVER” message when they studied the software coding that killed their cards, according to HackHU.com and other sites.)

dewey 7y ago

I just spend some time trying to dig up the old TV ads for the licensing fee we had in Austria where they also had some kind of detector van with antennas. Unfortunately I wasn't able to find it. I was always curious how that might work.

m0xte 7y ago
AFAIK they detected the emissions from the IF strip on old televisions with a directional yagi antenna mounted on top of the van. This possibility disappeared when the IC based IF sets were developed in the 70s and 80s.
- dewey 7y ago
  I still remember that van having an antenna like that on top. Might be the case.

trhway 7y ago

interesting that England is the country where they stopped require dog licensing because people would just ignore it. https://en.wikipedia.org/wiki/Dog_licence#United_Kingdom https://en.wikipedia.org/wiki/Dog_licence#United_Kingdom One would think that identifying an unlicensed dog is much simpler than detecting a TV behind the walls.

blunte 7y ago

Reminds me of the cat detector van. http://www.montypython.net/scripts/fishlic.php http://www.montypython.net/scripts/fishlic.php

Emma_Goldman 7y ago

The BBC also claims to be able to detect when anyone uses their online streaming service, IPlayer, though I suspect this may be a ruse to scare people away from watching without a licence. Curiously, the TV licence is a third of the price if you have a black and white television set.

NeedMoreTea 7y ago
Not so curious. When the colour licence was introduced, a colour TV was an expensive luxury, and a 12" b&w TV was standard fare for impoverished students. I think the relative differential has increased over the years as students came to rely on the portable telly being the cheap option. At the same time as introducing the colour licence, they abolished the radio licence. btw, as you have to sign in to view iPlayer these days - annoyingly even for radio, I am sure they can detect when people use it. It's not even a bit challenging. :)

boobePhuu7iet7i 7y ago

I never paid for a license. It's insane to be forced to subscribe to a handful of channels you may or may not be interested in. The "inspectors" have no legal right to enter your property, so you can simply tell them to fuck off.

coldtea 7y ago

How about a small flat fee everybody pays to sustain the national broadcaster? Whether they watch it or not is not relevant. It's a nation-wide service at their disposal. Either it's worth it to have, like a dam or a highway system or whatever, and it's ok for people to pay for it in taxes, or it's not, and it should close.

ktpsns 7y ago
That's the solution in Germany since a few years. It is called Rundfunkbeitrag and costs 20€ per month per flat.
- deleted 7y ago
  [deleted]
yjftsjthsd-h 7y ago
Because now you're proposing that people be charged for something even if they don't use it and don't want it.
- coldtea 7y ago
  Yes. In many countries that's how nation-wide infrastructure, services, art programs, and so on are funded. Not on a person per person basis. Not everywhere it's all about the individual and their whims. If the majority (well, through elected representatives) wishes to have and sustain a public good (whether a public broadcaster, or national health service, or arts grants, or whatever), individuals have no other say on the matter. Some countries believe in public goods, and in maintaining through taxes infrastructure to make citizens more educated, informed, cultivated, etc. If someone is a brut and could not care less, they don't get to dictate to the nation not to have those services. E.g. the German example of the tax for the national broadcaster a fellow commenter mentions: "Any household in Germany is legally obliged to pay this quarterly fee, regardless of whether or not you watch the TV channels or listen to the radio stations covered by it. It also covers media consumption online via on-demand services such as media players, streaming services accessed online via computer or smartphone, as well as in-car audio. Shared households are only required to pay this per household, so 4 students living together for example would only be liable for paying the fee once."

JackFr 7y ago

It seems like it would be so much easier to tax the TV's.

LandR 7y ago

I currently have no TV licence. I cancelled it over a year ago as I don't receive a TV signal in my flat. The TV is used for netflix, Amazon Prime, Youtube and the Playstation. I filled out the form to get my refund and you have to choose an option for why you don't need a TV. e.g. you are moving, you are in the military, gone blind or something etc etc. Not an option to tick "I don't watch TV". Anyway, I got the refund and within a week I was getting threatening letters from them saying I don't have a TV licence! Great joined up IT guys. The letters have continued at a rate of one or two a month ever since. I could probably make them stop by calling them, but I already filled out the form, I got my refund... I don't see why I should waste more of time helping them out. I expect at some point someone is going to come to my flat and request to see in the flat to check I'm not watching TV without a licence. If they do they won't be getting let in. It's the tone of the letters that is most annoying, they are quite threatening and they try to be intimidating. I can laugh it off and just bin there nonsense and ignore it, but I could see some people getting upset / intimated into paying, which is sad.

wlkr 7y ago
I get these letters regularly. On principle I refuse to deal with Capita/BBC/TVL and would rather they waste the money trying to contact me. There is no obligation to deal with them unless they get a warrant. Only once have they visited and left a calling card but fortunately I was out.

Nas808 7y ago

The entire concept of being charged a fee for broadcast TV, going as far as having enforcers driving around in vans seems very strange to me. But on the other hand, I am very impressed with the quality of programming the BBC puts out.

deleted 7y ago

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jhallenworld 7y ago

The TV license reminds me of the Church Tax that some countries have. This would not fly in the US at all..

zzo38computer 7y ago

I hope somone can figure out how the detection is working, perhaps by making experiments and see what is found to do.

YeGoblynQueenne 7y ago

>> The warrant stated that: "the optical detector in the detector van uses a large lens to collect that light and focus it on to an especially sensitive device, which converts fluctuating light signals into electrical signals, which can be electronically analysed. This "especially sensitive device, which converts fluctuating light signals into electrical signals" sounds remarkably like the human eye. Those signals, of course "can be electronically analysed". Emphasis on "can". Equivalently, "could".

pyman 7y ago

Why drive thousands of vans around the UK, hire contractors and spend tax payers money, when the government can ask Sky and Virgin to provide them with a long list of households that are paying for cable tv (~30 million)? It makes you wonder, doesn't it?