This is irrelevant.
Flock operates on the foundational constitutional model of "Our cameras are in public, there is not an expectation of privacy in public, therefore we can capture anything/everything our camera sees in any way possible" (including LPR logging and even video recording).
And thus, so does any other system of recording public activity and processing/storing data collected from it.
It quite literally does not matter what people do or don't do with the information. If someone does use the information for something illegal (like stalking) them the police aught to take a police report filed by said Flock employee seriously and perform an investigation within the bounds of the law and constitution.