Re What did governments get from harassing MLK, OWS, anti-war protestors, or any of the other hundreds of millions of people that were abused by governments throughout history?
Thats the fun next step. With tech like this you get every licence plate, passengers face, drivers face 24/7, cell numbers called, cell phone details in any area depending on a few main roads in and out of a community, protest area or meeting.
Private/public CCTV network sharing fills in more gaps.
Then the State or Federal gov can wonder how long they can keep the data for.. months, years, tens of years? If there is a limit in place, get the private sector to share/collect/sort it.
In the past agencies would have to be photographing, walking local car parks-noting plates, sitting in on political meetings.
Now the data just collects itself with no real legal limits other than "parallel construction" efforts.