Car number plates have a consistent, mandated font with a set of regular formats on high-contrast backgrounds that makes it almost trivially easy for computer vision to extract a number plate from an image of a car.
Cars are licenced transport. You are required to a) tax and maintain your vehicle b) identify who was driving the vehicle if you are the registered owner and requested to do so by the police and c) not obscure or obfuscate your number plate.
Faces are not licenced, are uniquely identifiable personal data - ignoring the enormous false positive detection rate from current technology - and everyone has one. Consider the implications for a supposedly free society (of which the United Kingdom no longer is one) where the state can draw arbitrary inferences from the presence of someone with a face that matches pattern X in location Y on date Z.
Your reply illustrates my comment that some people only see the worst or try to imagine only the worst.
If a facial recognition system is only linked to a database of wanted people then it won't be able to ID people not on that database. I.e. if it is no worse than a normal CCTV for everyone who is not wanted by the police.
Therefore, in principle there is no negative impacts in terms of privacy or liberty compared to existing CCTVs.
The only issue is technical: False positives (which I'm not sure the numbers would be 'enormous' at the moment). This is bound to improve over time and can be mitigated with the appropriate police procedures on how to respond to an alert by such a system.
for a supposedly free society (of which the United Kingdom no longer is one)
Of course if that's your opinion we're not going to be able to have a discussion on the topic...
Your assumption that the system throws away everything but the images of flagged people and number plates, and expires even those after some period of time, flies completely in the face of reality (e.g. the New York State Police were keeping all their collected ANPR data indefinitely [0]). A number of US states are making legal provisions to restrict how long ANPR data is retained for [2] - are they just tech pessimists too?
False positives (which I'm not sure the numbers would be 'enormous' at the moment)
A 98% false positive rate [1] seems quite enormous.
The Metropolitan Police’s system has produced 104 alerts of which only two were later confirmed to be positive matches
In another deployment:
overall only 234 alerts – fewer than 10 per cent – were correct matches.
At least in the UK you're not going to be stopped by a police officer with a gun drawn on the basis of a failed read [3].
In addition to false positives, the false negative rate must also be given. For example: if 100 "suspect cars" pass by, but only 5 are identified as suspect, then 95% of the suspects are still on the loose and the system is again much less effective.
This FOIA response [1] reckons that there was a test where the false-negative rate was 20%, but there's also this report [2] of a 30% false negative rate at the Notting Hill carnival. So to continue your example, out of 100 known wanted people walking past the system 20-30 got through without being flagged.
You're not contradicting my points, you are giving anecdotal examples of problems and bad implementations. The only assumption I made is that we can have such systems implemented in a way that is properly controlled and harmless.
> If a facial recognition system is only linked to a database of wanted people then it won't be able to ID people not on that database. I.e. if it is no worse than a normal CCTV
Yes, and it would still be able to match other possible suspects purely because they are on the wanted list.
Moreover, you are matching against _actual_ people meaning that whenever the system makes a mistake you are still arresting someone who isn’t wanted.
As points of fact, not everyone has a face, and it has not yet been proven that they are uniquely identifiable.
Never mind the possibility of Hollywood-quality fakes.
I have occasionally considered starting a religion with a tenet of wearing uniform clothing (subject to weather) and identical masks whenever out in public. There's ample precedent from other religions. I figure it might even be profitable, from selling the "official" uniforms and masks, and from the overpriced cafe in the meetings hall.
99.99% of people have a face. You don't make laws or social rules for the tiny minority, you make them for the vast majority. Exceptions and caveats to the laws/rules to protect the interests of the minority are fine. But the general structure should suit the needs of the general populace.
Comments
Car number plates have a consistent, mandated font with a set of regular formats on high-contrast backgrounds that makes it almost trivially easy for computer vision to extract a number plate from an image of a car.
Cars are licenced transport. You are required to a) tax and maintain your vehicle b) identify who was driving the vehicle if you are the registered owner and requested to do so by the police and c) not obscure or obfuscate your number plate.
Faces are not licenced, are uniquely identifiable personal data - ignoring the enormous false positive detection rate from current technology - and everyone has one. Consider the implications for a supposedly free society (of which the United Kingdom no longer is one) where the state can draw arbitrary inferences from the presence of someone with a face that matches pattern X in location Y on date Z.
Your reply illustrates my comment that some people only see the worst or try to imagine only the worst.
If a facial recognition system is only linked to a database of wanted people then it won't be able to ID people not on that database. I.e. if it is no worse than a normal CCTV for everyone who is not wanted by the police.
Therefore, in principle there is no negative impacts in terms of privacy or liberty compared to existing CCTVs.
The only issue is technical: False positives (which I'm not sure the numbers would be 'enormous' at the moment). This is bound to improve over time and can be mitigated with the appropriate police procedures on how to respond to an alert by such a system.
Of course if that's your opinion we're not going to be able to have a discussion on the topic...
Your assumption that the system throws away everything but the images of flagged people and number plates, and expires even those after some period of time, flies completely in the face of reality (e.g. the New York State Police were keeping all their collected ANPR data indefinitely [0]). A number of US states are making legal provisions to restrict how long ANPR data is retained for [2] - are they just tech pessimists too?
A 98% false positive rate [1] seems quite enormous.
In another deployment:
At least in the UK you're not going to be stopped by a police officer with a gun drawn on the basis of a failed read [3].
0: https://arstechnica.com/tech-policy/2012/09/your-car-tracked...
1: https://www.independent.co.uk/news/uk/home-news/met-police-f...
2: https://arstechnica.com/tech-policy/2015/03/virginia-passes-...
3: https://arstechnica.com/tech-policy/2014/04/due-to-license-p...
In addition to false positives, the false negative rate must also be given. For example: if 100 "suspect cars" pass by, but only 5 are identified as suspect, then 95% of the suspects are still on the loose and the system is again much less effective.
This FOIA response [1] reckons that there was a test where the false-negative rate was 20%, but there's also this report [2] of a 30% false negative rate at the Notting Hill carnival. So to continue your example, out of 100 known wanted people walking past the system 20-30 got through without being flagged.
1: https://www.whatdotheyknow.com/cy/request/use_of_automated_f...
2: https://theconversation.com/why-regulating-facial-recognitio...
You're not contradicting my points, you are giving anecdotal examples of problems and bad implementations. The only assumption I made is that we can have such systems implemented in a way that is properly controlled and harmless.
Yes, and it would still be able to match other possible suspects purely because they are on the wanted list.
Moreover, you are matching against _actual_ people meaning that whenever the system makes a mistake you are still arresting someone who isn’t wanted.
Faces aren't unique enough and innocent doppelgangers will eventually be abused.
As points of fact, not everyone has a face, and it has not yet been proven that they are uniquely identifiable.
Never mind the possibility of Hollywood-quality fakes.
I have occasionally considered starting a religion with a tenet of wearing uniform clothing (subject to weather) and identical masks whenever out in public. There's ample precedent from other religions. I figure it might even be profitable, from selling the "official" uniforms and masks, and from the overpriced cafe in the meetings hall.
99.99% of people have a face. You don't make laws or social rules for the tiny minority, you make them for the vast majority. Exceptions and caveats to the laws/rules to protect the interests of the minority are fine. But the general structure should suit the needs of the general populace.