LLMs don't need to hide anywhere to be dangerous, though. The danger can come purely from them reaching sufficient power together with some other idiot sufficiently crazy to use them to cause destruction.

I mean, in another thread somewhere around here, someone built an entire OS with an AI. What's to stop anyone with a sufficient taste for power to eventually use AI to cause havoc with it?

I think the underlying assumption in your post, which I believe is false, is that people are united somehow against catastrophe. They're not. There are plenty of people who participate in society currently but who would be more than happy to eradicate us normal people under different circumstances. Society often seems stable but it's far more fragile than we think.