Several people posted recently in a thread on women, mostly espousing feminist views - only to find that someone had declined to respond to their post, but instead browsed their history and downvoted every single comment or article they had ever posted.
I have two questions:
1. Why would you come to a site like this and pollute the karma system? How does it make you smarter? How does it make anyone else on the site smarter?
2. What would be a good technical workaround? In my mind, some system that detects mass-downvoting and flags a user for review would be preferable, but what should happen then? Should the system be more lenient to higher-karma posters? Who should perform the review process? What should be done with those whom the reviewer ascertains are abusing the karma system? I would prefer some kind of lesson that is more corrective than retributive - it seems to me that people who would perform this behavior are exactly the sort of people who need some of the lessons that this site provides. Any ideas?
I think it could certainly be wise to implement a limit on the rate at which one can downvote posts by a specific user, or, if that's technically difficult to implement, the rate at which one can downvote fullstop.
The more involved measures you suggest would require effort, but I suppose the question becomes: what is LessWrong for? If it's actively for improving rationality, such measures could be worthwhile, assuming we could find or reroute some moderators / mentors / monitors.