I don't know why the guy keeps coming back to Yahoo! Answers. Gregory Kohs has lost his account thrice already that I'm aware of.
What is his big sin, anyway? I don't know the official reason he's been kicked off each time, but the thing the pro-Wikipedia duckspeakers have against him is that he asks "push" questions—questions he already knows the answer to but with which he hopes to provoke other people to the realization that Wikipedia is completely worthless as a source of information on anything and completely unworthy of donations.
But given that thousands if not millions of people continue to trust Wikipedia as being "good enough," it is important for people like Gregory Kohs to continue trying to do everything they can think of to educate people about Wikipedia. If, in researching the answer to a question Greg posts, someone gets it across his thick skull that Wikipedia can be trusted with neither intellectual property nor money, it will have been worth it. Besides, a question is a question, regardless of whether or not the asker knows the answer.
I suppose Greg might comment on this post and disclose his new username on Yahoo! Answers. It doesn't matter if he does, the Wikipediots on Yahoo! Answers have already figured out what it is. In one of his latest "push" questions, the user calling himself "Death Panelist" (previously "GrimJack") wrote "And try not to lose your Yahoo! account this time, OK?" Which quite likely means that it was him who reported Greg for a violation. That's the kind of thing Wikipedia apologists expend their limited intelligence on: figuring out the identities of Wikipedia critics.