[stickfigure]

We probably all agree that a cellphone is closely associated with you and acts as a surrogate brain, so it gets treated as "you", at least as much as the _inside_ of your house or car.

You the right of free travel (with or without your phone). Automobiles are different. You can't take it everywhere; you can't park it everywhere; you can't move it about in secret (plates MUST be displayed, always).

You have an expectation of privacy for the inside of your car. But not the outside of your car. And even the inside... if it's visible from the windows, it's public.

[estearum]

The reason cell tower data is excluded from Third Party Doctrine has nothing to do with the contents of a cell phone. Cell tower data doesn't have any relationship whatsoever to the contents of the phone.

The relevant factors are:

1. It creates a near-complete picture of a person's whereabouts

2. It is effectively not optional to have and carry a cell phone today

You do in fact have a reasonable expectation that the government can't reconstruct a near-perfect timeline of your daily life without a warrant... obviously.

[stickfigure]

A cellphone is effectively you in the eyes of the law.

Any automobile may be driven by many people. Only 30% of households are single-person households.

We'll see how this plays out in courts. I'll bet the license plate readers survive. More skeptical about facial recognition though.

[estearum]

> A cellphone is effectively you in the eyes of the law.

No. I just laid out the reasons why cell tower data is different. It has nothing to do with whether a cellphone "is effectively you," which obviously it's not.

[nateb2022]

As Katz established, the Fourth Amendment protects people, NOT places. The assumption that "if it's visible from the windows, it's public" is a dangerous non-sequiter that completely falls apart under any form of jurisprudence.

Your understanding of privacy misapplies the plain view doctrine. Plain view allows the state to seize evidence provided that the officer seizing the evidence has a lawful right to access or observe the seized object. (Collins v. Virginia)

An officer glancing through a car window is performing a constitutional act.

However, were the state to compile a history of your car's location, which it does, that exposes your "familial, political, professional, religious, and sexual associations." (Jones) This compilation of data is an action legally defined as a search, since it turns up data NOT readily available in plain view. And this search takes place without warrant.