Hosting ethics
For example, a certain player joins a game hosted by me. Now, I happen to think (for instance) this particular player is a stat whore, a liar, and a rude arrogant asshole. Do I have a... well, moral right, as a host, to kick him? Yeah, given the small size of our community, refusing to play with player X or Y may lengthen waiting times (as if they weren't long enough). But that's not the point. The hypothetical problem I've described is ethics/netiquette-related.