It's all in the context then, the way I see it, they could just be using the software to automatically track targets through all the footage, where I work, we have about 30 cameras and tracking someone through them all is a pain. If I could highlight a person as they walk in, and then just have the software track them automatically, it would save me an incredible amount of time.
Imagine doing the same, in a crowd of thousands, with hundreds of cameras,over a huge area?
If they are just recognizing, recording and storing..... To what end? What is the purpose? I literally can't think of anything negative, I'm not defending the police, maybe I've succumbed to the brainwashing, but I really don't see the big deal?