I think there is an essay in there somewhere. The tools for looking for and correlating data are getting better faster than we can respond intelligently to them. I recall how silly I felt the government's TIA (total information awareness) plan was but its less silly now. But governments aside, what happens when person A takes a picture of person B who is sharing lunch with them, and behind them at a booth is Person C having a lunch with person D who should not be associating with person C. The tool picks up both person C and D's face and tags three recognizable people, B, C, and D in the photo. And person E, perhaps the spouse of person C, gets 'C was tagged in a photo' showing up in C's stream and it comes as a rude surprised to person E.

Kinda creepy.

Your scenario is highly unlikely.

First of all, find my face is opt-in, so person 'C' and person 'D' would have had to explicitly opt-in for this to happen.

Second you can control who can tag you in pictures - so person 'C' and person 'D' would have the opportunity to review the tagged photos before the tags become public.

Third - Find My Face won't create tags automatically. When person 'A' uploads the picture, Find My Face will look for faces in the photo and if it finds a person who has opted in to the feature it will suggest that the person be tagged. So person 'A' will see a prompt of the form 'Is this a picture of <person C>'? Most likely person A's response will be 'I have no idea' and they won't create the tag in the first place. This is especially true since tagging someone in a photo automatically shares the photo with them.