Yes, I am looking for an argument that justifies governments banning LLM development, which implies existential risk is likely. Many things are possible; it is possible Christianity is real and everyone who doesn't accept Jesus will be tormented for eternity, and if you multiply that small chance by the enormity of torment etc etc. Definitely looking for arguments that this is likely, not for arguments that ask the interlocutor to disprove "x is possible."

The nitter link didn't appear to provide much along those lines. There were a few arguments that it was possible, which the Nitter OP admits is "very weak;" other than that, there's a link to a wiki page making claims like "Finding goals that aren’t extinction-level bad and are relatively useful appears to be hard" when in observable reality asking ChatGPT to maximize paperclip production does not in fact lead to ChatGPT attempting to turn all life on Earth into paperclips (nor does asking the open source LLMs result in that behavior out of the box either), and instead leads to the LLMs making fairly reasonable proposals that understand the context of the goal ("maximize paperclips to make money, but don't kill everyone," where the latter doesn't actually need to be said for the LLM to understand the goal).