first law?

I have a hypothesis about online communities, which goes something like this: if you, as the moderator/owner/list-mom of an online community, find yourself in the position of having to say things like “Being an asshole is not acceptable behavior and will result in expulsion from this place” multiple times in multiple ways in some short interval of time, then that online community is already mortally damaged, whether you realize it or not.

I’m currently involved in a test of this hypothesis, unfortunately; something I have neither the time nor inclination for at the moment. I hope I’m wrong.

(Suggestions for dealing with “assholes in the midst” gratefully received.)