It's hope that Chatrie v. US automatically implies Flock searches require a warrant, but this is definitely not guaranteed - SCOTUS could easily go either way on this. For example, in his concurrence with the decision, Gorsuch relied on property rights, namely that Chatrie's agreement with Google regarding location history made this a warrant-required search. Obviously that doesn't apply in Flock's case.
SCOTUS has held for a long time that people don't have an expectation of privacy when visible in public. Digital recording and powerful search features certainly change the calculus on that, but there is a fundamental difference between a location tracked by a cellphone you purchased and own vs. just driving around where anyone can read your license plate.
SCOTUS has held for a long time that people don't have an expectation of privacy when visible in public. Digital recording and powerful search features certainly change the calculus on that, but there is a fundamental difference between a location tracked by a cellphone you purchased and own vs. just driving around where anyone can read your license plate.