Going by principles and precedents, I would say the user of the LLM will be responsible. Woke activists are trying to override this and push liability onto the developers of the models so it will depend who has better lobbyists.

the biggest difference is that the output is automatically generated content for human consumption* at scale.

* it remains to be seen if man or machine will be the biggest consumer of the content. It is entirely possible that the internet will become dominated by AI readers and writers instead of cats and naked activities, though these will likely become largely AI generated too, maybe not cats since they provide ample content by just being themselves