FRT is scary good at what it does. I've been at trade shows where vendors were selling this. At one they had a big screen set up to demo how the system identified people as they walked by. It drew a box around heads and followed people.

What the vendor did nt make clear (until after talking with them) was that it could track the crowd of people who passed by on the show floor and individually identify each one including when and how many times each one had passed by the camera in their booth. (They had actually turned that capability off for the demo as people's reaction to seeing it was shock and horror). That as a few years ago. I can hardly imagine the improvements in this technology that have been developed in the interim.

Couple the above with a database of facial recognition signatures and it's quite easy to see how this could be misused to invade privacy, etc.