Abberant Behavior in your Setting?

Someone pointed me toward a particular page over at the website of crusades.encyclopedia.com that reccounts some actions on the part of crusaders that is rather unsavory, so to speak.  If the practice of cannibalism didn't exist at all, then it would be no great feat to dismiss the claims outright, but such things do happen in some cultures, in some extreme circumstances, and in some crisis.  So the question for us becomes, how much of this if any do we add into our tabletop roleplaying game settings?  At the least, it is a good bogeyman to put out there as rumored in a neighboring setting location.