If you have a question about a thread or poster who “disappeared,” please DO NOT post an inquiry. In probably 95% of such cases, the thread (or poster) that vanished was an attention-seeker – a spammer , sock, or troll. They’re out for any attention, even negative attention, and we don’t want to give it to them. They disappear, as do their posts. And as do posts about them.
So, if you have a question about such, please email a moderator. DO NOT post your question. DO NOT give these folks any publicity, acknowledgement, or recognition.
As always, when you see a ban without an announcement - particularly of a poster who’s been around for a significant amount of time - please ask a moderator.