> 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

I heavily disagree with the sentiment that modern 'ALPRs' are the same as following around an individual in public. No police officer, sheriff, state trooper, etc. is able to follow an individual across the entire country and catalog their every move 24/7. They have jurisdictions they're allowed to operate in. Additionally, the level of tracking these cameras provide (via their accompanying software) is nearly on par with placing a GPS tracker on a vehicle (which requires a warrant btw), and they're tracking every vehicle that passes, not just vehicles involved in a crime. Our travel history is protected by the 4th amendment because of the intimate details it can reveal about an individual's life. That is ultimately why Chatrie v. US was decided, not because of the specific technology utilized. It's the same case for Carpenter v. US and US v. Jones; both of which were instrumental in deciding the outcome of Chatrie.

I encourage people to go read the opinions of the justices that decided these cases. For example Justice Kegan had this to say in Chatrie v. US [1]:

> The Court began its analysis by reviewing what it had said about a different way of tracking “physical location and movements”: the use of a GPS device to monitor a vehicle. In United States v. Jones, five Justices had agreed that such tracking counts as a Fourth Amendment search because “individuals have a reasonable expectation of privacy in the whole of their physical movements.” That made sense, the Carpenter Court thought, even though the movements occurred in public. Prior to the digital age, pursuing a suspect “for any extended period of time was difficult and costly and therefore rarely undertaken.” As a result, “society’s expectation has been that law enforcement agents and others would not—and indeed, in the main, simply could not—secretly monitor and catalogue every single movement of an individual’s car.” A new technology should not transform what individuals had reasonably thought they could withhold from the Government.

[1] https://www.supremecourt.gov/opinions/25pdf/25-112_0am4.pdf