Re: In my opinion the only effective moderation is none at all.
I believe there may be liability reasons not to allow certain posters with racist or socially deviant behavior to continue posting on a forum. If you owned the forum, you are liable for lawsuits from your users, and I wouldn't want to assume that a jury wouldn't award a plaintiff with emotional damages in this day and age.
Outside of these extreme cases, I agree that most situations can be dealt with without moderation. My previous post pretty much outlined a possible policy to use if the regular policy of no moderation did not work.