If someone has access to cameras on the ground it doesn't seem like it would be too difficult to integrate this with a facial recognition system
"Secret Cameras Record Baltimore’s Every Move from Above (bloomberg.com)": https://news.ycombinator.com/item?id=12347595
"Additionally, they discovered that when the suspect walked away from the shopping center, he’d passed in front of a ground-based security camera. Accessing that footage and reviewing Cooper’s mug shots on file, they found a possible match."