But the headline and narrative paint a way too optimistic (if you’re anti-Flock) picture of Chatrie’s impact.
In particular the search identified by Chatrie (Google’s database of expected-private location records, including movement in the home and other private spaces) has almost no analog in third-party-owned recordings of public movement.
The fourth amendment does not say “private conversations,” so when police started tapping phones, the courts focused on whether the phone tap physically intruded on somebody’s house, papers, or effects. Police apparently could tap phone conversations by watching reflections on a nearby window, and the fourth amendment didn’t apply because there was no physical intrusion. The “reasonable expectation of privacy” test come from Katz v. US ( https://supreme.justia.com/cases/federal/us/389/347/ ) where the Supreme Court realized that whether there was a physical intrusion was irrelevant.
This is a modestly different situation than one concerning warrantless tracking of phone locations, if for no other reason than my phone oftentimes in my pocket. It is not always visible to onlooking bystanders. And even if it isn't, externally there is no reliably way to differentiate one iPhone from another. In comparison: license plates, when in public, are always visible, and very easy to discern from one-another (different state-unique numbers); so in my mind the expectation of privacy is far lower.
I abhor what Flock does, but I'm not sure I see a constitutional argument for why what they do is unconstitutional.
You can still pay your use tax and be a good citizen, and in fact, its probably a better demonstration of your duties as a citizen to protect the right to privacy and say to your local governments that have a history of abusing and selling vehicle registration data to 3rd parties that you do not tolerate that.
Happy to share more, the sites for Montana registration can be shady but the dirt legal one is great.