From what I understand these systems are legal because there is no expectation of privacy in public. Therefore any time you go in public you cannot expect NOT to be tracked, photographed, and entered into a database (which may now outlive us).
I think the argument comes from the 1st amendment.
Weaponizing the Bill of Rights (BoR) for the government against the people does not seem to align with my understanding of why the Bill of Rights was cemented into our constitution in the first place.
I wonder what Adams or Madison would make of it. I wonder if Benjamin Franklin would be appalled.
I wonder if they'd consider every license plate reading a violation of the 4th amendment.
Not quite. There's been precedent set that seems to imply flock and other mass surveillance drag net operations such as this do violate the forth.