I don't think it reflects upon the forum as a whole - we just picked up some single NRx-er with way too much time on his hands a while back and there's not much that can be done about it, as he will just keep making alts. You can basically harvest karma for downvoting by making a large number of low quality comments, because everyone is apparently downvote-averse. The last time this happened the user in question managed to become a top poster. I think he's basically aiming to alter the group's composition by targeting left wing individuals who are sensitive to negative feedback.