Very cool project, I didn't know about this until EFF just did short piece on how this org is fighting a cease and desist from the company enabling cops to mass-surviel the movements of the public.
IDEA: I don't have the technical chops to do it, but I'd loooove if someone used open-source license plate reader software and enabled people to set up a network of raspberry pies with inexpensive cameras attached them to surveil the surveiller: these devices could track cop plates as they move around cities, which could then be fed into a live, open map
I bet they wouldn't love getting a taste of their own medicine.
There is Open CV and Optical Character recognition so I would guess what you are suggesting is doable.
I have seen PI projects where a camera pointing at a private parking space in say a block of flats can alert you if someone else is parked in your space. That usually uses colour of the car to work and relies on both parties not having the same colour of car.
