Discourse is most productive near the very limits of civility.
Pliny's Postulate:A person who believes that their's is the only absolute and therefore valid world view, cannot logically use any argument against any other viewpoint derived from the doctrine of fairness.
Essentially there aren't any. If at some time some vitriolic troll happens to start annoying me in my own house, then that may change. But before that can happen, more than 5 people will have to actually visit the site so I'm not too worried about that. Sorry to add the verification step, but unless spammers are going to pay me - no free lunches!