Though they were certainly outcasts and reviled, have you ever read about the grotesque Beane family of Scotland? Strange, strange story.
The difference here is that when the king heard about this abomination, he summoned an army of 400 and scoured the countryside for the offenders. In the case of the "civilized" Aztecs, the king also scoured the countryside, but for the same reason as Sawny Beane: shopping.
That is about the freakiest thing I've ever read.
There is also an interesting account of this family in "The Bedside Book of Bastards" (Hardcover) by historian Dorothy M Johnson, who also wrote the stories on which the movies "Jeremiah Johnson" and "A Man Called Horse" were based. The book is out of print, I believe, but can still be found through Amazon.com
It's a collection of historical accounts of some of history's most notorious "badasses" (/grin), but told with a humorous twist and a sort of Paul Harvey "rest of the story" flair. It also makes a great coffee table book when priggish guests or relatives drop by!