As the Chief puts it, the "hippie" gang try to "escape reality by pretending to be like King Arthur and his men." They engage in motorcycle-jousting and pepper their speech with archaic language. According to the prime minister's aide, "outside of the fact that they were amazingly ruthless they were surprisingly polite...Before he pushed me out [of the car], one of them said, 'Fare thee well and get ye lost'."
Their hangout is Dee Dee's Diner on Washington DC's west side.
[Episode #71: "The Mild Ones".]