The Mad Hatter, aka Matthew Moulton has a pretty dreadful reputation. His main hunting grounds were on usenet where he'd become such a pest that people had looked up his personal information and sent him threats of all kinds.
When he was first causing trouble on the org, some of the more dilligent members of the forum delved a little into his past.
this should give you a clue as to the kind of reputation he had.
It appears that he enters a community, is all "peace and love, happy camper, aren't communities the best!" and then someone points out that something he said was incorrect. At that moment his head explodes and he goes into flame and mockery mode and never ever shuts up provided there is still someone there to argue with him.
After his first banning he made numerous duplicate accounts which were banned as soon as they were created. He then used proxy servers to hide his ip address to make his accounts less detectable - but of course hates not being able to tell anyone about his wonderful l33t skills and blows his own cover.
This went on for a fairly long while. He promised to bring the org down to its knees blah blah blah and then gave up.
He returned a month or so ago but didnt seem to be causing any trouble. Of course that was until someone said he was wrong and... well, as you've seen in numerous threads.