I realize the file hosting costs money, but karanta does bring up some very valid points, and the point brainstew made - that if the rules of the site being enforced would keep things fairly even keeled.
A lot of the comic hosting sites that do voting, for instance, will put up a page for people clicking in to state if they want to vote for this comic, OR, if they have been tricked/mislead to that site, to click in a report abuse field. Sounds like a perfect way to cut down on traffic that isn't here for the content.