YouÃ(TM)re not wrong, but the issue with flock and similar is not so much being witnessed in public as it is being algorithmically analyzed and suffering consequences as a result. Which is an erosion of the presumption of innocence. It also provides a an easy tool for stalkers/oppressors/paychopaths that is really difficult to defend against.
The big thing with Flock is the Flock "social network" of cameras. That is their heavily advertised feature and what makes Flock cameras different from all other ALPRs out there.
You see, when Flock started, they sold their cameras to private individuals to monitor vehicles passing through their property (HOAs, parking lots, etc). But each was basically isolated from each other - just because Home Depot had Flock cameras doesn't mean your HOA could get information on that.
But then Flock started selling to governments, and they realized they could offer a big network. If your city joined the Flock network, then your city LEOs could search across the entire Flock network. The more cities that joined, the more valuable this access was.
And that lead to the problems of today where the network is abused by people for purposes that were not law enforcement related, like stalking romantic interests, exes, etc. Because the network was nationwide, this mean if your ex moved to a new city with Flock, they could be tracked just the same. No justification beyond some arbitrary "case" needed.
Flock sells it as "track a stolen vehicle across the nation". Which is far less effective since a single license plate can hit many different vehicles because many states have similar license plate number schemes. A stolen motorcycle lead to a takedown of a family in an SUV because their license plate matched except state. Because of oddball New Jersey license plates, Jaguar (the car company) have to re-plate their entire fleet of vehicles because the Flock camera only reads the big numbers on the Jersey plates, which match another stolen vehicle. Studies of the effectiveness of the alerts reveal it to only be about 20% effective.
All the other ALPRs like Axon(Taser) and such, either record it local to the city, or limit the network to where they are, so the city only has access to the city's network of cameras. Sure you break the nationwide stolen vehicle thing, but honestly do you think car thieves are stupid enough to ride around with stolen plates for more than a day? It's one of the first things they change.
And Flock knows the problem - as cities cancel their Flock subscriptions, the network gets less valuable. It's why when cameras get taken down, they're often replaced by Flock. A city who cancelled their Flock contract reclaimed all the cameras, only to find new ones put up. Basically it's like the city loses access but Flock retains the right to keep spying. Either that or they're like weeds.