As you break rules the mods add karma to you. After a certain level, you get banned. Dunno if they are actually using it or just haven't figured out how to disable it.
I disable that karma and reputation crap on my board since I would know who was being an ass and who isn't.

Here there are so many members and mods involved that maybe they need it to keep track of the asshats. What better way to track the problem kids than with their own accts, right? Also it lest the rest of us know who the tools are.