> We know the technology works, but using it in supermarkets to deter shoplifters and prevent attacks on staff is very different from deploying it to catch people on a public transport network. Success in a shop means no such people coming in. Success for the police trying to catch people means people being caught. In that respect the trial doesn’t appear to have been very fruitful.

ahahaha. "My magical face detection software worked because (according to our detection software) none of the undesirables came in!"