White supremacist groups is a blanket term but if you break it down to specific groups, some could be considered OC. At least that's what sons of anarchy taught me. I've personally never seen a white power group in real life but I hear they exist out west in bigger numbers.
But while we're on this topic, who thinks the nation of Islam is a cult? If you really read about their beliefs outside of the race stuff they seem as crazy as scientologists..