7. Aryan Brotherhood
Bald, with a lot of tattoos, violent and rough is a typical Aryan Brotherhood member. This is a racist criminal organization, operating in almost every prison in California, Texas, Arizona, Ohio, and Indiana. For the past two decades, the gang grew into organized crime syndicate, relying on prostitution and drugs distribution as their income source. This group counts around 33,000 violent felonies, in and out of prison.