What a silly comment. That's just the South Park underpants gnomes story with some extra steps. If there are vulnerabilities in food or energy production and distribution systems then those will eventually be found exploited by humans hackers regardless of whether LLMs are used or not.

What’s the legal mechanism for holding an LLM accountable for those actions? What’s the legal mechanism for holding human hackers accountable? Do you see the asymmetry?

Worse, you’re missing the entire point. Agents presently have the capability of doing society scale harm. It doesn’t matter if a human hacker initiates it or its fully autonomous, absent safety measures the harm is plausible. So hand wave away the rationality of safety measures but you haven’t actually shown why my point is invalid: AIs present abilities are sufficiently advanced to warrant safety measures.