First, if it was the CIA or NSA themselves in conjunction with the Feds or State LE conducting mass surveillance on the population rather than outsourcing it to either Flock or Palantir: they have the legal precedent on fabricating charges they deem as "dissident activity", imprisoning protesters including vigilantes who are critical of the state. Usually it's a politician who passes legislation under the guise of "protecting kids".

Second, if let's say Flock or Palantir is the one conducting mass surveillance: they can't arrest people themselves since they are not law enforcement. They would collect someone's data but still, cannot put people behind bars themselves. All they're doing is data harvesting rather than pursuing people based on their social credit score, but vigilantes who oppose mass surveillance can at least still roam around in the street.

I've heard a case about a group of vigilantes taking down Flock cameras since it has become another flashpoint of growing bipartisan anger against the tech industry (that's only speaking of tackling on a corporation spying on people) rather than the government themselves doing that to the population.

However, what happens if they did the same with government surveillance (as in the cameras are operated by the CIA / NSA in which they alert authorities)? The response is different since authorities & government can arrest, imprison or kill vigilantes on the spot if caught on tampering with the cameras.