[kjaftaedi]

Finding this person at random in an area of 100s of millions of people, and recognizing him 10 years later from a photo where his face is totally blurred?

I feel like there's another piece to this story that is being hidden.

The Facebook and Google finds are likely both came after whatever the original clue was.

My guess is they are protecting an informant.

[michael1999]

Parallel construction is also used to launder electronic surveillance sources, so wiretap is just as likely. Although running machine vision on every picture in google maps does sound like something the sigint people would do.

[kjaftaedi]

Agreed, but with the target unwilling to contact even his family in 10 years, and being in a completely different country than the one looking for him .. these things make the wiretap theory a little watery as well.

Your second theory would only work assuming google is participating in blanket facial recognition with various law enforcement.. which while possible, would be a small scandal if revealed.