
UK police say 92% false positive facial recognition is no big deal - neverminder
https://arstechnica.com/tech-policy/2018/05/uk-police-say-92-percent-false-positive-facial-recognition-is-no-big-deal/
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leepowers
Reminds of similar stats on stop and frisk - where only a small percentage of
stops actually resulted in some sort of criminal conviction. And only a tiny
fraction of those convictions were related to the original reason for stop and
frisk[1] - discovering illegal weapons.

From the cop's perspective they're looking for a needle in a haystack. Public
pressures are especially intense when it comes to anticipating and preventing
terrorist attacks or curbing violent crime. But predicting rare events is very
difficult. Due to the nature of the problem it's going to be mostly haystack
(false positives) most of the time.

So I can understand why the UK police remain unperturbed by 92% false
positives. And why the NYPD was largely indifferent to a similarly high rate
of failure with stop and frisk.

The problem though is _we are the haystack._ There's a bit of the snake eating
it's own tail here. In order to keep you safe we need to own your privacy. In
order to protect your person from violent crime must be able to search your
body at any time. Whatever freedom might be I can be sure freedom is not
_that_.

[1] [https://www.theguardian.com/world/2013/nov/14/stop-and-
frisk...](https://www.theguardian.com/world/2013/nov/14/stop-and-frisk-new-
york-conviction-rate)

~~~
DoreenMichele
_Whatever freedom might be I can be sure freedom is not that._

Yeah, it's all kinds of _throwing the baby out with the bathwater._

It's common for parents to tell kids stuff like "If someone other than this
short list of names wants to touch your private parts, scream." And I wasn't
comfortable telling my kids that. I felt that would be robbing them of the
very innocence I desired to protect.

Instead, I taught them that affection required permission and if anyone did
not respect their answer of "no," come get me. That worked remarkably well.

I don't know how to translate that to adult security issues out in the world.
But there are definitely inherent problems with the current course we are on
that increasingly reminds me of what I heard about East Germany: that everyone
was reporting on everyone just to try to cover their own butt because everyone
lived in fear of the government and it's surveillance state tactics.

~~~
leepowers
The adult response is to acknowledge the trade-offs involved and to learn to
live with a certain amount of risk. A free society is always going to be
vulnerable to terrorist attacks to some degree. Reasonable policies might
reduce this risk by 25%, 50%, 75%, 90%, etc. But they'll never reduce the risk
to zero. So the conversation can't be _how do we make sure this never happens
again._ Instead it must be an analysis of the trade-offs involved in securing
against rare events while maintaining the freedom of movement and privacy that
a free society requires.

Facial recognition in the UK, the mass phone metadata collection in the US and
abroad, stop and frisk in NYC; public support of or indifference to these
measures depends on the perception of the trustworthiness of government. That
is, for populations that perceive that government as "on their side", the
tradeoffs these policies require appear innocuous or beneficial.

So what if the NSA is storing my metadata? They're the good guys trying to
catch terrorists. From this perspective the risk of bad government actors is
smaller than the risk of terrorism.

So what if cops go hands-on with someone walking down the street? They're
finding illegal guns and contraband, and bad guys with warrants. The
inconvenience of being stopped is a cost worth paying for safer neighborhoods.

But the fulcrum of government can quickly swing from trust to oppression.
There are decades where nothing happens; and there are weeks where decades
happen. We cannot keep evil people from attaining power. But we don't have to
give them rope with which to hang us. Privacy protections, respect for bodily
autonomy, adherence to the rule of law, and the decentralization of economic
and political power are all bulwarks against tyranny.

~~~
ataturk
Again, as mentioned above, read up on East Germany. All your questions about
"why is this bad?" have already been lived by tens of thousands of hapless
people.

------
OscarCunningham
The problem isn't the inaccuracy, it's that people will inevitably treat it as
far more accurate than it is.

------
jonny_eh
As long as it's just flagging people and not arresting/harassing them, I don't
think the error rate matters that much.

Even a system that says "there's a 10% chance this guy is a wanted criminal"
seems useful.

~~~
perl4ever
The probability of _any_ positive, and the probability of a _false_ positive
are quite distinct things. It makes a big difference if, of that 10%, 99% are
false positives, or 1% are.

If 99% are false positives, then there is another form of harm being done even
if the police are not abusive. Time and energy are being spent to vet those
positives. It's like medical tests that say you have cancer. If there are a
lot of false alarms, people waste effort and don't catch the real issues.

The number of false negatives also matters, and is also not determined by your
10% figure. That is, out of the 90% that weren't flagged, how many should've
been?

