There's been one abusive person on SO that I've been watching, whose reputation was somewhere around 20, which suddenly jumped today to 181. The answer to this quickly became clear, however, when you look at this question: http://stackoverflow.com/questions/1419816/problem-in-xmldatasource. He has created an alternate account, which he rated up for answering his own questions, enough that it can now vote for him. It has voted for nearly every one of his answers or questions, bringing a 20 reputation to 181.
Is there anything that can be done to deal with situations like this, where a single user is purposefully gaming the system with two accounts to raise their reputation?
As well, on mechanics--are there any mechanics in place to offer some sort of guard, to prevent a user from continually voting another user up? This might aid in situations like this, or situations where RL relationships devolve into continual point-fishing.
Edit: This specific situation seems to be finished now, with both users no longer existing. Thank you, everyone, for the help.