The Millwall Bushwackers are a football firm associated with Millwall Football Club. Millwall have a historic association with football hooliganism, which came to prevalence in the 1970s and 1980s, with a firm known originally as F-Troop, eventually becoming more widely known as the Millwall Bushwackers, who were one of the most notorious hooligan gangs in England. On five occasions The Den was closed by the Football Association and the club has received numerous fines for crowd disorder. Millwall's hooligans are regarded by their rivals as amongst the stiffest competition, with Manchester United hooligan Colin Blaney describing them as being amongst the top four firms in his autobiography 'Undesirables', and West Ham hooligan Cass Pennant featuring them on his Top Boys TV YouTube channel, on which their fearsome reputation for violence was described.