Mine is from a character I played many years ago and started using as a screen name various places (like Yahoo!). The character was an experiment in how far I could take the notion of Chaotic and Good without diluting either. Mercule Corin was a pacifistic elven ranger who had a knack for flustering paladins, city guards, and other authority figures while being totally honest, upstanding, respectful, and fun to be around.
After hanging around various boards, I've started to go by Sobek elsewhere. Also a character name, but from Mage: the Ascension. He was a former Oakland drug dealer and thug turned Order of Hermes scholar of Khemitan mysteries. He was about as subtle as a nuke, inflamitory, and was perfectly willing to use mind-numbingly vulgar effects whenever convenient.
The latter moniker may be more appropriate.