What Exact Law Did the Coldcard Thief Break?

Wildly hypothetical question, please do not downvote me to oblivion. I am not excusing anyone here, kinda playing the devil's advocate out of curiosity.

So, a guy tried some random keys (coming from a space of points, a space with a reduced dimension than the expected 256 bit entropy, but that's all very rhetorical and technical) with a computer and broadcast some transactions (basically, signatures) using the keys he discovered with his own computer. That is it at a basic level, right?

He did not use a wrench attack, did not break into someone's home to steal a paper with passwords, did not drug or interact with any victim to coerce a password out, did not send scam texts promising investment returns. He is just coding on his computer talking to the Blockchain.

So is that really...illegal? I mean hypothetically, if he is caught, and he hires the top law firm in the world, what charge would stick? So far as I can see, he is just playing a guess-the-number game with the Blockchain sitting in his basement.

And if we allow (to the extent the Bitcoin advocates and Libertarians have any capacity to allow) a government to prosecute him, then what kind of precedent does it set with regard to a state's power to prosecute someone purely for interacting with the Blockchain and trying signatures/key combinations?

Are we ready for a political regime (basically, the state machinery) to come in and tell everyone how exactly am I supposed to interact with the Blockchain, that takes precedence over whatever the consensus protocol allows?

EDIT:

Yes, from the comments I can get there are laws and charges depending on jurisdiction that would stick. But I am far more concerned about the precedent that can be set by penalising someone for interacting with the Blockchain (a system not owned by a bank or a specific corporation) in a way that is just something the community did not like.

It opens a door to the political class to co-opt and regulate/alter the Blockchain in a way they deem convenient to protect a status quo or their regime and any interaction outside the political norm can be considered...well, illegal.

Worst, seems like in this case, the whole Bitcoin community will cheer at the prospect of crucifying the coldcard thief for justice, welcoming such a possibility.