An interesting piece on True-believer syndrome from The Skeptic's Dictionary:
http://skepdic.com/truebeliever.html (lots of other interesting topics also)
Neatly explains why overwhelming evidence of a hoax won't shake a true-believer's faith in the unbelievable.
This is why I quit the Newcomer Rescue League. AA oldtimers can often react loudly, abusively, threateningly and sometimes violently when they are presented with overwhelming evidence of the hoax of AA. They will "go to any lengths" to avoid, condemn, delegitimize or eliminate any threat to their belief system. The AA system filters out non-believers and concentrates the true believers in the ranks of the oldtimers. It's an effective way to build an army of true-believers who are willing to do anything to preserve the fantasy of the hoax BUT horribly damaging to those who refuse to become true-believers.
Also worth a read is the Wikipedia page on the Wisdom of Crowds: http://en.wikipedia.org/wiki/Wisdom_of_crowds.
Using the definitions there AA is an excellent example of an "Unwise crowd". This unwise crowd is a self regulating filter: keeping those people that are psychologically vulnerable to the hoax and removing those with independent, intellectual and logical capability. Thus the AA system ensures continuance of the homogeneity of the unwise crowd - it will never get wiser or more diverse - it will never make better decisions. To maintain this unwise crowd requires no external control - it is completely self regulating. It's an evil dictator's wet dream.