People keep making this claim that Flock "explicitly sells access to data", but the link you provided doesn't demonstrate that, and Flock contracts I've read contradict the claim.

I think what's happening here is that people are trying to colloquially define "selling access to data" to fit the camera data sharing that Flock enables, and then saying that because you have to pay to be a Flock customer to get access to that data, they're effectively selling it. I don' think that's how data brokerage laws work. Flock doesn't own the data they're providing access to, and they're providing that sharing access with the (avid!) consent of their customers.