I mostly stick to AIBU, with rare forays to other pages.
I thought as a general rule Mumsnet usually only removed threads where the OP was a troll, or where there were a lot of unpleasant personal attacks.
Recently I've been reading a few threads where the thread has then disappeared, with the message 'OP has requested that we remove this', for no very obvious reason.
AIBU not to understand this? In that case, surely any OP could request removal if people weren't agreeing with them?