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Millimeter-wave machines at airports today are totally and completely useless. Germany's transportation administration reported a 54% false positive rate for th

Millimeter-wave machines at airports today are totally and completely useless. Germany's transportation administration reported a 54% false positive rate for these pieces of rubbish. You are better off randomly searching people by flipping a coin. These are multi-million dollar security theater failures and it bothers me more that people are considering buying even more derivatives based on this garbage technology for anything. Police officers or security guards could just literally point one at anyone they find suspicious and use it to justify an illegal search, because it will most likely read yes, even if the person's pockets are totally empty.

yzmtf2008 7y ago
Having a high false positive rate isn't really the end of the world for security screening though, as long as they have a low false negative rate, which I don't see many articles complaining. Even at 50% false positive rate, it's 50% time saved compared to patting down every one. Additionally, these machines highlight potential areas to search more carefully, so there's probably even more time saved there.
- close04 7y ago
  If your antivirus or car alarm start flooding you with fake warnings you will ignore then more often than not. It’s human nature and you can’t really change it without some drastic measures like severe punishment or constant checks to keep people on their toes. And this last one just kicks the ball further up the ladder but still to a human with the same predisposition.
eis 7y ago
> Millimeter-wave machines at airports today are totally and completely useless. Germany's transportation administration reported a 54% false positive rate for these pieces of rubbish. You are better off randomly searching people by flipping a coin. Edit: note that it seems I had a wrong understanding of the term false positive rate, ignore this comment. Statistics doesn't work like that. The false positive rate is pretty meaningless in this context. It only determines how much useless manual work is performed after the machine flags you incorrectly. You should look at the false negative rate in order to determine how much of a security plus they bring. That being said, I think the whole airport theater is ridicolous. If terrorists wanted to kill people, they literally have thousands of alternative ways to achieve that.
- cookingrobot 7y ago
  In this context of using them in public spaces it’s the false positive that matters most. The complaint is that the machines basically always alarm, which means the only thing they can be used for is making up a bogus excuse to manually search / harass someone based on no real suspicion.
  - eis 7y ago
    But they don't always alarm according to the number that was presented. It alarms twice as many times as it should. That's not good and I certainly wouldn't want these in public spaces. But you can't just look at the false positive rate and how much more work and unpleasant/unnecessary searches they cause. You have to take into account the false negative rate to get a complete picture. Manufacturers and the people who want these machines will always err on the side of too many false positives than too many false negatives. Again, I personally think that these machines have no place in public spaces, no matter their hit/miss-rate.
    - Dylan16807 7y ago
      > It alarms twice as many times as it should. That's not what a false positive rate is. It alarms on half of everyone that goes through. It's utter garbage as a first-line test.
      - eis 7y ago
        I think this is a misunderstanding. From Wikipedia [1]: > A false positive error, or in short a false positive, commonly called a "false alarm", is a result that indicates a given condition exists, when it does not. So a 50% false positive means also that in 50% of alarms the condition was actually true. What you mean is a 50% alarm/trigger rate. Which, depending on how many people do have something on them that should trigger the alarm, would result in a far far higher false positive rate. 1: https://en.wikipedia.org/wiki/False_positives_and_false_negatives https://en.wikipedia.org/wiki/False_positives_and_false_nega...
fyfy18 7y ago
I wonder how well a tool would work that anonymises people - so those with power won't consciously, or subconciously, target people with brown skin and large beards - while still showing how they are behaving. You could even use cameras to monitor heartbeat [0] and body temperature. [0] https://techcrunch.com/2016/12/05/oxehealth-uses-cameras-to-monitor-your-heartbeat-from-across-the-room/ https://techcrunch.com/2016/12/05/oxehealth-uses-cameras-to-...
sametmax 7y ago
Not to mention the culture of suspicion and insecurity it builds up. It's insane, and terrible for democracy.
- ericmcer 7y ago
  Having just gone through the airport yesterday I definitely relate to this. Even when walking through security totally clean you feel helpless, it is probably the closest we come to feeling the pressure of a totalitarian govt. in the USA, it makes me appreciate the bill of rights and not take for granted what it gives us.
13of40 7y ago
Back when they originally came out, I'm sure you'll recall that the operator was basically looking at a high resolution nude image of the person being scanned. The false positives came when people protested and they changed the display to a pixelated cartoon that shows "suspicious" areas as illuminated squares that need to be patted down by a human.
- djsumdog 7y ago
  No, those are two totally different technologies. One was x-ray (and terribly dangerous to use in that way) and the current in millimeter wave (which literally cannot make a nude image. The best it can do is the cartoon outline)
  - 13of40 7y ago
    This article is possibly where the poster above me read the 54% FP statistic, and its point is not about resolution but that the different wavelength of energy used will show things like sweat as surface, and combined with the automated detection it produces a lot of false positives. https://www.propublica.org/article/sweating-bullets-body-scanners-can-see-perspiration-as-a-potential-weapon https://www.propublica.org/article/sweating-bullets-body-sca...
timdev2 7y ago
In the context of an administrative search at the airport, security guards can already just search whomever. Arguably, the machines are able to clear ~50% of travelers and exempt them from a more intrusive search.

yzmtf2008 7y ago

Having a high false positive rate isn't really the end of the world for security screening though, as long as they have a low false negative rate, which I don't see many articles complaining. Even at 50% false positive rate, it's 50% time saved compared to patting down every one. Additionally, these machines highlight potential areas to search more carefully, so there's probably even more time saved there.

close04 7y ago
If your antivirus or car alarm start flooding you with fake warnings you will ignore then more often than not. It’s human nature and you can’t really change it without some drastic measures like severe punishment or constant checks to keep people on their toes. And this last one just kicks the ball further up the ladder but still to a human with the same predisposition.

eis 7y ago

> Millimeter-wave machines at airports today are totally and completely useless. Germany's transportation administration reported a 54% false positive rate for these pieces of rubbish. You are better off randomly searching people by flipping a coin. Edit: note that it seems I had a wrong understanding of the term false positive rate, ignore this comment. Statistics doesn't work like that. The false positive rate is pretty meaningless in this context. It only determines how much useless manual work is performed after the machine flags you incorrectly. You should look at the false negative rate in order to determine how much of a security plus they bring. That being said, I think the whole airport theater is ridicolous. If terrorists wanted to kill people, they literally have thousands of alternative ways to achieve that.

cookingrobot 7y ago
In this context of using them in public spaces it’s the false positive that matters most. The complaint is that the machines basically always alarm, which means the only thing they can be used for is making up a bogus excuse to manually search / harass someone based on no real suspicion.
- eis 7y ago
  But they don't always alarm according to the number that was presented. It alarms twice as many times as it should. That's not good and I certainly wouldn't want these in public spaces. But you can't just look at the false positive rate and how much more work and unpleasant/unnecessary searches they cause. You have to take into account the false negative rate to get a complete picture. Manufacturers and the people who want these machines will always err on the side of too many false positives than too many false negatives. Again, I personally think that these machines have no place in public spaces, no matter their hit/miss-rate.
  - Dylan16807 7y ago
    > It alarms twice as many times as it should. That's not what a false positive rate is. It alarms on half of everyone that goes through. It's utter garbage as a first-line test.
    - eis 7y ago
      I think this is a misunderstanding. From Wikipedia [1]: > A false positive error, or in short a false positive, commonly called a "false alarm", is a result that indicates a given condition exists, when it does not. So a 50% false positive means also that in 50% of alarms the condition was actually true. What you mean is a 50% alarm/trigger rate. Which, depending on how many people do have something on them that should trigger the alarm, would result in a far far higher false positive rate. 1: https://en.wikipedia.org/wiki/False_positives_and_false_negatives https://en.wikipedia.org/wiki/False_positives_and_false_nega...

fyfy18 7y ago

I wonder how well a tool would work that anonymises people - so those with power won't consciously, or subconciously, target people with brown skin and large beards - while still showing how they are behaving. You could even use cameras to monitor heartbeat [0] and body temperature. [0] https://techcrunch.com/2016/12/05/oxehealth-uses-cameras-to-monitor-your-heartbeat-from-across-the-room/ https://techcrunch.com/2016/12/05/oxehealth-uses-cameras-to-...

sametmax 7y ago

Not to mention the culture of suspicion and insecurity it builds up. It's insane, and terrible for democracy.

ericmcer 7y ago
Having just gone through the airport yesterday I definitely relate to this. Even when walking through security totally clean you feel helpless, it is probably the closest we come to feeling the pressure of a totalitarian govt. in the USA, it makes me appreciate the bill of rights and not take for granted what it gives us.

13of40 7y ago

Back when they originally came out, I'm sure you'll recall that the operator was basically looking at a high resolution nude image of the person being scanned. The false positives came when people protested and they changed the display to a pixelated cartoon that shows "suspicious" areas as illuminated squares that need to be patted down by a human.

djsumdog 7y ago
No, those are two totally different technologies. One was x-ray (and terribly dangerous to use in that way) and the current in millimeter wave (which literally cannot make a nude image. The best it can do is the cartoon outline)
- 13of40 7y ago
  This article is possibly where the poster above me read the 54% FP statistic, and its point is not about resolution but that the different wavelength of energy used will show things like sweat as surface, and combined with the automated detection it produces a lot of false positives. https://www.propublica.org/article/sweating-bullets-body-scanners-can-see-perspiration-as-a-potential-weapon https://www.propublica.org/article/sweating-bullets-body-sca...

timdev2 7y ago

In the context of an administrative search at the airport, security guards can already just search whomever. Arguably, the machines are able to clear ~50% of travelers and exempt them from a more intrusive search.