I ask because I'm wondering how much China's announcement here is a stunt that goes well beyond the state of the art.
Facebook's FR is nowhere but FB, forget it. There is a range of false positive rates, depending upon how an FR system is employed. The best resource for the state of the art is probably this: https://nvlpubs.nist.gov/nistpubs/ir/2017/NIST.IR.8173.pdf (FYI, my work is vendor "L")
I say all this as a happy Google User and a developer of Face Recognition Technology. Those in the know realized privacy has been dead for awhile now. Generally computers can do most anything we can do in say 200 ms or less with the proper training data, and they generally do it better than humans. The giants have all the data they need, they just need to spend time annotating training sets and running analysis over larger and larger sets until they reach super human performance.
https://www.theguardian.com/uk-news/2017/aug/05/met-police-f...
I would suspect if there has already been one public announcement then it will actually have been used covertly for quite a while.
http://www.bbc.co.uk/news/uk-england-leicestershire-33132199
Look at current surveillance cameras in the US as an example. There are a lot of them now, but data is held by a wide variety of people and institutions, and most of them just don't care about it unless something criminal happened.
If an individual school or workplace adds FR to their cameras such that they alerted to strangers in restricted areas, I wouldn't worry about that at all. If they own the data and have their own FR profiles, that's cool by me.
But that's very different than China's effort, where they're clearly working toward complete coverage of 1.4 billion people, with strongly centralized control. Now that they have president-for-life Xi, that's a lot of authoritarian potential.
The real question to ask yourself is of all the groups you belong to (HN readers, people in their 20s, etc, etc) will any of them fall out to the point that the system flags you as deserving of "driving while black" treatment at any point in the future.