Tolerance

I'd add that I agree that Jon's suggestion to surface the information that "this guy has been filtered regularly and by many people" would be a good step. It's still gameable, of course, but it's a good social cue. Think of it as people walking away from the Creep at a party - maybe not as good as throwing the Creep out, but still sends the signal that "we don't approve of what this guy is doing." Worst case, it helps people understand that this person is not representative of the community, and best case, perhaps surfacing that signal (like the red/green/yellow cards discussed in the original article) gives people an opportunity to learn.