Hello, hello. And apols for the lack of MNHQ presence on this thread lately.
OK, first of all, we are very happy to move AIBU threads that really shouldn't be in AIBU (maybe because the OP is a newbie and doesn't know about our other Topics). Please do report any that you see.
Also, just to be clear, we don't moderate AIBU any differently than any other area of Mumsnet - posting in AIBU is definitely not a licence to be ruder to/less respectful of other posters than you would be if you were posting in another Topic.
If you see posts in AIBU that break our Talk Guidelines, please report them to us and we will delete them if they do - and, if necessary, mail the poster with a warning or even ban her/him completely.
For those who don't already know, Mumsnet is post-moderated - this means no one at MNHQ reads posts before they are posted up (we couldn't possibly keep up!); instead, we rely on you all to flag up posts that break our rules by reporting them to us (using the Report link above the post in question). In other words, Mumsnet's (and AIBU's) tone is largely set by Mumsnetters.
Having said all that, we take your many points on board, and we will have a think about taking a tougher line with AIBU posts that are reported and maybe having a twiddle with the "please respect our Guidelines" note at the top of AIBU threads.