Traveling extensively the past year I have noticed the following which are probably all coming into our lives soon. (a) In many countries border entry is accompanied by a fingerprint scan which will be either a left and right index finger scan or a scan of the whole left hand. The scans are done at inbound border crossings in conjunction with the passport check. (b) In many countries both border exit and entry are paired with the taking of a photograph. In some places it appears the exit photograph is validated automatically by software. (c) In some cities, the subways have security checks at entry and in those places photographs are taken, non obviously, by the security equipment. I am not sure how effective these systems are at tracking. I guessing ideally governments would like to pair these photos with a passive probe of something carried on the body like a phone or official id, something that could link the photo to an already verified identity. (d) On country entry, purchases like SIM cards for local telephone service or public transportation pass cards can only be acquired if one presents an official id. Manual computer entry usually links the card to the presented id.
And here is a prediction, getting a record of faces and fingerprints, and tracking movement is on the agenda right now. In the future there will be a equally focused agenda to acquire records of peoples DNA. In countries where there is nationalized health service, it will eventually be required. Aquisition will begin when the cost of storing, acquiring, and searching that DNA information becomes cheap enough.