I just had this idea: How about making it really easy to be promoted to a volunteer down-vote moderator for an hour or so, just a button away. The task would be to downvote comments with mean and extreme language. The down-votes would count twice during that time and the actual moderators would be able to monitor what the volunteers are doing and to act accordingly in the event of misuse. That maybe results in less work for the actual moderators and at the same time it’s maybe more effective. I think, I would happily do this on a lazy sunday afternoon as a service to the community.