Eh donkey... read a book about them, it's not made up.
I don't even need to read that book, i saw the documentary, it runs once a month on N24.
You are right, i just say that the Aryan Brotherhood is terrifying, and i would never want to come across them, but on the other hand you can say that their "concept" has quite some stupid flaws.
They kill their own kind just as anyone else, these guys don't care for race, they kill who they want.