Hmm, "cameras reported a 97.3% match". I would assume that for a random person, the match level would be random. 1÷(1 −.973) ~ 37. IE, 1 in 37 people would be tagged by the cameras. If you're talk China, that means matching millions of people in millions of malls.

Possibly the actual match level was higher. But still, the way facial recognition seems to work even now is that it provides a consistent "hash value" for a face but with a limited number of digits/information (). This be useful if you know other things about the person (IE, if you know someone is a passenger on plane X, you can very likely guess which one) but still wouldn't scale unless you want a lot of false positives and are after specific people.

Authorities seem to like to say DNA and facial recognition caught people since it implies an omniscience to these authorities (I note above someone throwing out the either wrong or meaningless "97.3% value). Certainly, these technologies do catch people but they still limited and expensive.