Would you be happy with a public "petcat tracker" site that published your personal location and image 24/7 whenever you are out in public, from data collected from Flock and other similar products? If you think that would cross a line, you do have some expectation of privacy even in a public place.

Right: This kind of law is supposed to conform to the common expectation, not dictate it!

We all might expect someone could take a photo of us walking down the sidewalk, but that's not the same as "expecting" to be followed by a virtual (or even literal) drone-swarm that constantly catalogues our every movement cross-referenced to potential interactions with everyone else.