Comment We tried and failed years ago (Score 4, Insightful) 55
More than 10 years ago, my company tried to do facial recognition in an airport in Europe, for their security service. Alas, they didn't know about the "birthday paradox", and tried to match about 1,000 criminals against several thousand passengers. They shut it down when the system identified someone's grandmother as a male member of the Baader-Meinhof gang.
The (birthday) paradox is caused by trying to match each passenger against 1,000 criminals, not just one. Even with only a 1% error rate, there will be 10 false positives and negatives per passenger. And we don't have anything like a 1% error rate.
We need a 1/infinity error rate (:-)) Otherwise innocent grandmothers will be pulled aside, while actual criminals will breeze on through.