I mean, anyone can create a new account on HN and post "I am literally going to kill Joe Biden tonight", and perhaps they actually plan to do that too, and maybe they'll even pull it off, but that doesn't mean HN orchestrated a conspiracy to kill Joe Biden.
The general policy is "look, but don't touch", and while I don't really trust the userbase in general to adhere to that, the people running the site (mostly this Null guy, as near as I can tell) seem fairly dedicated to this.
Personally I think the internet wold be better without the site, but I also think there's a sore lack of nuance here, and people accept certainly dubious claims a little bit too readily (turns out not everything on the internet is the whole story, or even true in the first place).