The creepiest thing I've discovered is, when it comes to the real true believers, you can't even try to reach them by appealing to their self-interest. You can't say "what if it was your father with the same beliefs who was shot?" because they all hate their parents and grandparents. You can't appeal to the idea of children growing up in a world full of political violence, because none of them have or like kids. You can't ask them to think about their own friends being gunned down over politics, because their friendships are shallow and conditional and they would happily turn over their friends to a firing squad if they ever thought they were "Nazis." You can't even say "what if someone disagrees with you and kills you for your beliefs?" because they all hate themselves and want to die.