The NSA will run Mythos against the entire US population and it will find the patterns. Powerful computer purchases. Energy consumption suddenly spiking. HN comments demonstrating intent and/or contempt for the glorious self-evident freedom preserving laws of the United States.

Then they call your local law enforcement with an anonymous tip about this suspicious dude who's long overdue for a totally random home inspection.

When has enforceability ever been a concern of the government? This is the same government that had anti-sodomy laws on the books until the Supreme Court ruled it unconstitutional in 2003.

Making it illegal even without having a realistic means of enforcing it still chills behavior, and so just because it isn't practically enforceable in the general case doesn't mean it isn't without consequences.

Same way they detect if you do business with Russia, North Korea, Iran. They don’t detect 100% of the cases but the punishment are severe enough to deter most companies.

Whistleblowers. Personal use would still be possible of course.

It's not out of the realm of possibility to do AI audits. I'm not saying it's a good idea or likely, but certainly something they could do.