I've decided to take a hardline on such names. Some will gripe that their freedom of speech is being restricted, but I think that's pretty silly. Wikipedia is not the right place to get your jollies by tweaking people. And if you have some political message you want to get across you can just write a biased article, ha ha.
(Seriously, my point is that wikipedia is not the place for such things. The user pages are pretty much laissez-faire, anyway.)
To be fair, if we're not going to allow CRUCIFIEDCHRIST, we probably can't allow a number of other polemical names, even ones that are not offensive to most people. For example 'GhandiIsGreat'.
I know we have a problem sometimes with badly chosen names (to put it mildly!). One I have heard some comment about is CRUCIFIEDCHRIST which I agree is in very bad taste, as it appears to mock the beliefs of many Wiki users. (Either that or it is someone with a Woodrow Wilson-style Christ complex!) It would be as unacceptable as if someone called themeselves BUSHWARMONGER, LAPDOG BLAIR or BELSEN.
Well, "Belsen" is a real name, in addition to being a concentration camp. So *if* someone has that name, for real, and if it was not intended to be political.
--Jimbo