This is probably not a helpful comment because it's basically a daydreamers fantasy, but here goes...
Doesn't all the surveillance concern go away if we just remove license plates from cars? Our plates identify us nearly perfectly.
Flock provide more than just ALPRs. They also have systems that track people.
It actually annoys me that people focus purely on the ALPRs when the other cameras are arguably much worse.
The reality is that most people are tolerant of, if not supportive of surveiling car traffic. If tracking vehicle movements on public roads is such a bad thing, there'd be overwhelming support for removing license plates from vehicles. The whole purpose of a license plate is to facilitate surveillance of vehicles.
But of course, most people aren't in favor of that. They realize that cars are dangerous and behavior like speeding and running red lights needs to be claimed down on. When people are victims of crimes they like it when the police are able to track down the perpetrators - and traffic cameras are good at facilitating that. Outside of the HN bubble there's at lot less reflexive rejection of cameras.