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I don't understand the pessimism about this. In any real-world scenario this type of system would be followed by human review of the photographs, followed by ac

I don't understand the pessimism about this. In any real-world scenario this type of system would be followed by human review of the photographs, followed by actual investigation. Nobody is proposing arresting all 600 people straight away. Whittling 90,000 photos down to a set of 600 is a major accomplishment. Even if 599 of those are false positives, that 600th person would probably never have been caught, because it wouldn't have been feasible to review all 90,000 photos manually.

mLuby 7y ago
>Even if 599 of those are false positives, that 600th person would probably never have been caught. Society needs to accept that some percentage of crimes will invariably occur. Our question is "what maximum level of crime can we accept?" which then determines the time and resources required to achieve that level. I have no patience for this "zero-tolerance" rhetoric.
- kartan 7y ago
  > "what maximum level of crime can we accept?" I agree with you. Said that way seems that you are given up. I think that it can be better to say "do you prefer to catch 0.5% more criminals or to reduce 0.4% deaths by cancer". Or something like that. People usually want 100% safety, that is not possible to achieve, and to try to get it they will give away thousands of lives that could have been saved with the time and effort invested in that impossible goal.
- DangerousPie 7y ago
  I don't disagree with your point. It doesn't really have anything to do with the question at hand though. All I'm saying is that these tools are clearly doing a useful job and pretending like false positives are an insurmountable problem is a bit silly.
  - rndgermandude 7y ago
    Are they tho? Are they doing a better job than say police randomly checking people? Let's actually do some crude math to try to estimate how many new cops we'd need to hire in Germany just to check out those false positive hits. I mean, what's the point of such a system if you do not check out the hits and make sure, right? Let's assume it takes police 15 mins to check out a potential hit in person (finding the person, checking their identify and asking some questions), and they work in teams of 2 to be able to secure each other. The Deutsche Bahn alone says in 2018 they had 5.7 million passenger in Germany per day traveling by rail[1]. Let's assume all the train stations get equipped with with this tech and let's assume their 0.67% false positive rate holds. That's 38,190 checks you need to do on innocent people, per day, or 1591.25 checks per hour. A two person team can do 60 / 15 = 4 checks per hour. So you need to have 400 such teams at any given time. A shift is only 8h not 24h and people only work 5/7 days per week, so 400 * 2 * (24/8) * 7 / 5, so you need to hire at least 3,360 police officers (well, probably more like 5000, because we completely disregarded a lot of variables, such as vacation days, etc) just to harass DB rail passengers who were incorrectly classified as threats, nationwide. Remember, those are all false positives, not one of those people is actually a criminal the system is meant to be looking for. IIRC an average police officer costs the state about 90K per year on average in Germany. So you'll be spending 300+ million EUR per year on harassing innocent people just because your tech is kinda shitty. Now if those 3,360 police offers would do actual useful work instead and prevented or solved some crimes... Also, I don't want to be that person who happens to have a similar enough face to some criminal so the face detection triggers on me all the time. [1] https://www.deutschebahn.com/resource/blob/3992284/f9331633c8a19470629f9e3aa6d5fe8c/20190328_bpk_2019_daten_fakten_en-data.pdf https://www.deutschebahn.com/resource/blob/3992284/f9331633c...
    - DangerousPie 7y ago
      Admittedly I don't have any data for this, but I think it's fair to assume that this number of 600 would go down to 10-20 or so after a quick human review of the data. So I think your estimate of 15 min per "hit" is wildly overstating things. And again I don't think you're asking the right question to begin with. There is a whole separate argument to be had about whether we as a society actually want these kinds of systems and whether we think they are worth the cost (whether they require 300 or 3000 additional officers). But this system is being developed under the assumption that people do think it's worth it, and it does a pretty good job of making it a lot cheaper than it would otherwise be. I wouldn't call that a failure. As a side-note, I would imagine this would not actually be used routinely in every single station, at least not in the beginning. You could only activate it when needed to catch very high-profile criminal. For example after the attack on the Berlin Christmas market the terrorist managed to travel all the way to Italy (?) before being stopped. If the German police could have fed his photo to this system that would have been extremely helpful, even if it would have meant a couple hundred officers having to review photos for a day.
stordoff 7y ago
False negative rate seems like it would matter here as well, if it leads to people being discarded and _never_ considered.
nitwit005 7y ago
> Nobody is proposing arresting all 600 people straight away. Even though no one is proposing such a thing, it's basically guaranteed multiple police forces will do just that. I know that sounds ridiculous, because it is, but essentially every technology handed off to police forces gets misused in the worst way you can imagine. Not all the time, of course, but some of the time. I really like the idea of tasers, but unfortunately the claims that they're used as torture devices have a lot of validity.
klyrs 7y ago
> Even if 599 of those are false positives, that 600th person would probably never have been caught... But if 599 innocents are harrassed by the cops, then in all likelihood, the system does more harm than the crime it's seeking justice for

mLuby 7y ago

>Even if 599 of those are false positives, that 600th person would probably never have been caught. Society needs to accept that some percentage of crimes will invariably occur. Our question is "what maximum level of crime can we accept?" which then determines the time and resources required to achieve that level. I have no patience for this "zero-tolerance" rhetoric.

kartan 7y ago
> "what maximum level of crime can we accept?" I agree with you. Said that way seems that you are given up. I think that it can be better to say "do you prefer to catch 0.5% more criminals or to reduce 0.4% deaths by cancer". Or something like that. People usually want 100% safety, that is not possible to achieve, and to try to get it they will give away thousands of lives that could have been saved with the time and effort invested in that impossible goal.
DangerousPie 7y ago
I don't disagree with your point. It doesn't really have anything to do with the question at hand though. All I'm saying is that these tools are clearly doing a useful job and pretending like false positives are an insurmountable problem is a bit silly.
- rndgermandude 7y ago
  Are they tho? Are they doing a better job than say police randomly checking people? Let's actually do some crude math to try to estimate how many new cops we'd need to hire in Germany just to check out those false positive hits. I mean, what's the point of such a system if you do not check out the hits and make sure, right? Let's assume it takes police 15 mins to check out a potential hit in person (finding the person, checking their identify and asking some questions), and they work in teams of 2 to be able to secure each other. The Deutsche Bahn alone says in 2018 they had 5.7 million passenger in Germany per day traveling by rail[1]. Let's assume all the train stations get equipped with with this tech and let's assume their 0.67% false positive rate holds. That's 38,190 checks you need to do on innocent people, per day, or 1591.25 checks per hour. A two person team can do 60 / 15 = 4 checks per hour. So you need to have 400 such teams at any given time. A shift is only 8h not 24h and people only work 5/7 days per week, so 400 * 2 * (24/8) * 7 / 5, so you need to hire at least 3,360 police officers (well, probably more like 5000, because we completely disregarded a lot of variables, such as vacation days, etc) just to harass DB rail passengers who were incorrectly classified as threats, nationwide. Remember, those are all false positives, not one of those people is actually a criminal the system is meant to be looking for. IIRC an average police officer costs the state about 90K per year on average in Germany. So you'll be spending 300+ million EUR per year on harassing innocent people just because your tech is kinda shitty. Now if those 3,360 police offers would do actual useful work instead and prevented or solved some crimes... Also, I don't want to be that person who happens to have a similar enough face to some criminal so the face detection triggers on me all the time. [1] https://www.deutschebahn.com/resource/blob/3992284/f9331633c8a19470629f9e3aa6d5fe8c/20190328_bpk_2019_daten_fakten_en-data.pdf https://www.deutschebahn.com/resource/blob/3992284/f9331633c...
  - DangerousPie 7y ago
    Admittedly I don't have any data for this, but I think it's fair to assume that this number of 600 would go down to 10-20 or so after a quick human review of the data. So I think your estimate of 15 min per "hit" is wildly overstating things. And again I don't think you're asking the right question to begin with. There is a whole separate argument to be had about whether we as a society actually want these kinds of systems and whether we think they are worth the cost (whether they require 300 or 3000 additional officers). But this system is being developed under the assumption that people do think it's worth it, and it does a pretty good job of making it a lot cheaper than it would otherwise be. I wouldn't call that a failure. As a side-note, I would imagine this would not actually be used routinely in every single station, at least not in the beginning. You could only activate it when needed to catch very high-profile criminal. For example after the attack on the Berlin Christmas market the terrorist managed to travel all the way to Italy (?) before being stopped. If the German police could have fed his photo to this system that would have been extremely helpful, even if it would have meant a couple hundred officers having to review photos for a day.

stordoff 7y ago

False negative rate seems like it would matter here as well, if it leads to people being discarded and _never_ considered.

nitwit005 7y ago

> Nobody is proposing arresting all 600 people straight away. Even though no one is proposing such a thing, it's basically guaranteed multiple police forces will do just that. I know that sounds ridiculous, because it is, but essentially every technology handed off to police forces gets misused in the worst way you can imagine. Not all the time, of course, but some of the time. I really like the idea of tasers, but unfortunately the claims that they're used as torture devices have a lot of validity.

klyrs 7y ago

> Even if 599 of those are false positives, that 600th person would probably never have been caught... But if 599 innocents are harrassed by the cops, then in all likelihood, the system does more harm than the crime it's seeking justice for