I recently noticed a joke post; a user intentionally asked and answered a question that was a very subtle mockery of research-level physics papers and had no application as an actual question on this site. I've got a sense of humour, it was pretty funny, so I thought "we can let this slide. Close the question, but enjoy the joke while it's here" But I checked out his account anyway. It seems this user (not going to name names for privacy's sake, and [redacted] other reasons) has maybe 1 or 2 out of about 40 posts that are remotely serious. All of his posts are "jokes" aimed at intentionally misleading, asking nonsensical questions, or generally mocking physics in some way. If reading one of his answers, it is important to keep in mind the entire time that it is a joke. Some answers can seem very sane an reasonable because of his ability to use jargon. The important thing is that upon closer inspection, many of them say nothing or say the wrong thing seemingly intentionally. Granted, some of them are pretty funny, but the fact remains that it's damaging to have someone running around giving false facts or generally making us look bad/disreputable.
Thus, I'd love to have the discussion about at what point we decide something should be done and what to do in the case that they are way out of line.
To start it off, obviously we're all a big fan of something that's funny. So I assume it goes without saying that if you want to throw some jokes into a question or answer, feel free. I just think there should still be some serious content. Sometimes, an answer can be entirely silly and still be acceptable, an example being https://physics.stackexchange.com/a/70851/23473 where the top answer is entirely silly. But I think it becomes unaccpetable when, instead of a one-time thing, a user is constantly posting questions/answers that do more harm than good.
As for what to do when one is found, to that I have no answer. What would you say would be the appropriate action for an intentionally disruptive user?