In 1965, the editor of The Nation asked Hunter S. Thompson to write a story about the Hell's Angels Motorcycle Club, as they're officially known. The article quickly led to a book deal, and, the next year, the Gonzo journalist published Hell's Angels: The Strange and Terrible Saga of the Outlaw Motorcycle Gangs. Reviewing the book for The New York Times, Leo Litwak wrote:
Hunter Thompson entered this terra incognita [the world of the Hell's Angels] to become its cartographer. For almost a year, he accompanied the Hell's Angels on their rallies. He drank at their bars, exchanged home visits, recorded their brutalities, viewed their sexual caprices, became converted to their motorcycle mystique, and was so intrigued, as he puts it, that "I was no longer sure whether I was doing research on the Hell's Angels or being slowly absorbed by them." At the conclusion of his year's tenure the ambiguity of his position was ended when a group of Angels knocked him to the ground and stomped him...
Hunter Thompson has presented us with a close view of a world most of us would never dare encounter, yet one with which we should be familiar. He has brought on stage men who have lost all options and are not reconciled to the loss. They have great resources for violence which doesn't as yet have any effective focus. Thompson suggests that these few Angels are but the vanguard of a growing army of disappropriated, disaffiliated and desperate men. There's always the risk that somehow they may force the wrong options into being.
This clip, which aired on Canadian television in 1967, describes the circumstances that led up to the Angels giving HST a beat down. The misogyny that's on display will make you shudder.