They definitely need to require a specific and VALID JUDICIAL WARRANT for ANYONE to access Flock databases.
You know these companies will fight that tooth and nail because it would drastically reduce their revenue streams.
That would be a start but imo not enough. If police decide they need to track your vehicle, and can convince a judge of it, and get a warrant, they can place a tracker. Flock and similar systems open more information to them than that process does. They don't get to track you retroactively before the date of the warrant, for one thing.
When the data is received and not needed for a warrant or other charge the data should be instantly deleted. No backups, no nothing. All over in 15 seconds or less.
I don't know... I haven't given too much thought to the specifics of flock cameras, but...
There is no expectation of privacy in public places. There is no 4th amendment issue here that I can see. Now, if the car was parked in your garage and the police showed up to see the car in your garage, then yes, a warrant is required.
That said, I wouldn't mind some oversight on the use of flock database. I would support a police officer or detective requiring a capatain's approval to search the database, so there is a senior officer's approval on the record.
The problem, to me, isn't the camera, it's the license plate. I don't think the license plate on the car is in the same class as "being secure in your papers". A license plate is evidence that you registered the car for safe operation on public roads. Having a flock camera recording your license plate is no different than when Lovely Rita records your license plate number on a parking ticket or an automated toll camera records your passing.
I'm open to debate on this, but this is my first take on the issue.
-PJ