Mine symbolizes weakness, and my attempt to stomp it out. THWHACK! THWHACK! THWHACK!
But really, SC has been my CB/internet handle since college in the 90's. There were/are a lot of non-bathing, granola eating, eco-terrorist wannabe losers in school which liked to show their disdane for the military, government and "The man." This was one way to piss them off.
The avatar is just the best thing I could come up with. Personally, I think it sets a much subtler emotional response than a guy with a club.