Actually it was Samuel Blanning who reimposed Gregory Kohs's most recent siteban from Wikipedia, and the reason for banning was legal threats.
http://en.wikipedia.org/w/index.php?...er:M yWikiBiz
The reason he remained sitebanned is because none of Wikipedia's 1278 administrators was willing to give him yet another chance.
http://en.wikipedia.org/wiki/Wikiped...administrators
http://en.wikipedia.org/wiki/WP:BAN#Community_ban