>>chaps+(OP)
Easy solution for Flock problem: get rid of visible license plates. Make them 2x1" of size and RFID-readable, give readers to police, problem solved.
Not-that-easy solution is legal ban for such surveillance.
None of these both will happen though.
You accepted TSA and PRISM, you will get used to Flock too.
Next is Flock but for people, with face recognition.