[Kamq]

> This is not complicated: If you run a telegraph wire between El Paso and Juárez, the executive has the Constitutional authority to tap it to intercept communication to or from a non-citizen not in the United States, warrant-free.

That's not correct at all. It would only fall under federal overview if it's commercial (Article 1 section 8 clause 3 of the constitution gives congress the right to regulate commerce with foreign nations).

The Feds don't just get to do anything they want by default. All powers that aren't specifically given to the feds are defaulted to either the states or the people.

[twoodfin]

This is, flatly, nonsense. For example: Executive agencies conduct warrantless border searches unrelated to commerce around the clock.

[Kamq]

It's dumb, but Wickard v. Filburn makes basically anything involving physical goods "commerce". I'm sure there's a ruling somewhere that says something like: people entering the country subtly alter the restaurant market (not really any dumber than the Wickard v. Filburn rationale), and therefore the feds have a right to search everything.

I think it would be a lot harder to do that with speech though. Maybe you could argue that the telegraph line itself impacts international copper markets or something, but there are non-tangible based communication methods.