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UK Police Say 92 Percent False Positive Facial Recognition Is No Big Deal (arstechnica.com)

An anonymous reader quotes a report from Ars Technica: A British police agency is defending its use of facial recognition technology at the June 2017 Champions League soccer final in Cardiff, Wales -- among several other instances -- saying that despite the system having a 92-percent false positive rate, "no one" has ever been arrested due to such an error. New data about the South Wales Police's use of the technology obtained by Wired UK and The Guardian through a public records request shows that of the 2,470 alerts from the facial recognition system, 2,297 were false positives. In other words, nine out of 10 times, the system erroneously flagged someone as being suspicious or worthy of arrest.

In a public statement, the SWP said that it has arrested "over 450" people as a result of its facial recognition efforts over the last nine months. "Of course, no facial recognition system is 100 percent accurate under all conditions. Technical issues are normal to all face recognition systems, which means false positives will continue to be a common problem for the foreseeable future," the police wrote. "However, since we introduced the facial recognition technology, no individual has been arrested where a false positive alert has led to an intervention and no members of the public have complained." The agency added that it is "very cognizant of concerns about privacy, and we have built in checks and balances into our methodology to make sure our approach is justified and balanced."

4 of 189 comments (clear)

  1. Intermediate false positive rate by larryjoe · · Score: 5, Interesting

    despite the system having a 92-percent false positive rate, "no one" has ever been arrested due to such an error

    I may have concerns about the civil liberty impact of broad-net surveillance systems in general, but the algorithmic deficiencies of this particular system are portrayed incorrectly in this article. I.e., the front-end of the system (the facial recognition system) has a 92% false positive rate, but together with the post-processing in the back-end, the total system has a false-positive rate of 0%. This is similar to saying that the object detection failure probabilities for a ADAS system need to be viewed in the context of the entire system, and it's the performance of the total system that is significant.

  2. Bad maths or fishing by Anonymous Coward · · Score: 3, Interesting

    2,470 alerts - 2,297 false positives = 173 true positives.
    >450 people arrested from "facial recognition efforts".

    Either that means there were >277 false arrests due to facial recognition, or they are counting arrests due to "facial recognition efforts" as also including the results of things they found when the searched people based on those false positives.

    Since they claim "no one has ever been arrested due to such an error", so this means that both that the number of successful arrests has been inflated to make the system look more useful, and that the system's primary function is to justify illegal searches.

    1. Re:Bad maths or fishing by thegarbz · · Score: 3, Interesting

      Or (and I'm going out on a limb here) you're getting data from two different sources which haven't been normalised for time, duration, or public relations content.

  3. Re: Let's be positive by Anonymous Coward · · Score: 3, Interesting

    Hmm, but again, I don't think it has to do with skin colour but with ethnic upbringing, the set of core values, the level of pride and its worth against the worth of other humans life. E.g. Afghanistan is a country of virtually all-white people. Yet, of all the lethal violent crimes among recent migrants in Europe, most of them is done by Afghan young men. Or people from Balkans, or people from most parts of former Soviet Union, so often actors in crimes, even organized crime, also all white.

    Black people either come from African tribal cultures where inter-tribal tensions and violence is a norm, or are descendent of slaves who were systematically humiliated and now they have this urge to overcompensate by exerting their self-esteem and dangerousness.

    Haiti had its revolution, but it din't have its merchant and intellectual elite to form the leadership and successful state organization. Revolutions are executed by revolting masses, but successful ones are usually prepared, supported, and finally, exploited by social stratum just beneath the previous (and subsequently beheaded) top. When all the leaders a country has at its disposal are warrior higher ranks, it will get ... wrong order of priorities, so to speak, as well as very literal, as in "bloody", power struggle. But then again, in history of many similar nations there has been a way out, provided one strong (tyrant) leader emerges at the top and makes proper moves to create new elite out of selected individuals in its young generation. However, unlike some other (white) countries, Haiti neither had no access to universities with long tradition, nor skilled ship-builders and sailors to arrange a merchant fleet for export of its produce. Finally, after freedom comes, the worst of jobs, jobs only slaves would do, will be left undone. Ergo, your example is not representative.