Not sure I agree. The only difference I see is the idea that there's no expectation of privacy while driving on public roads. That's potentially a huge difference, certainly, but I don't think it makes the negative outcome here quite as likely as you think.
Otherwise, it's the same: Google's database is a third-party-owned record of people's movements in public, and Flock's database is a third-party-owned record of people's movement in public.
The ruling in Chatrie had nothing to do with an expectation of privacy, or lack thereof. It was about the dragnet nature of the surveillance. And in that respect, I don't see any meaningful difference between Flock's and Google's systems.
Otherwise, it's the same: Google's database is a third-party-owned record of people's movements in public, and Flock's database is a third-party-owned record of people's movement in public.
The ruling in Chatrie had nothing to do with an expectation of privacy, or lack thereof. It was about the dragnet nature of the surveillance. And in that respect, I don't see any meaningful difference between Flock's and Google's systems.