The original firm associated with Millwall was known as F-Troop.
The hooligan firm still exists today. However, the firm is not as large as it was at its height in the 1980s. This is due in part to ex-Millwall chairman Theo Paphitis’ introduction of a membership scheme following the events outside The New Den on the evening of the Birmingham City play off semi-final in May 2002. Sergeant Russell Lamb of the Metropolitan Police Service, a veteran of the May Day and Poll Tax riots, described this as the worst violence he had ever experienced.
In January 1988, when Millwall were knocked out of the FA Cup by Arsenal in a third round match at Highbury, 41 Millwall hooligans were arrested after clashing with Arsenal’s firm The Herd.
In August 1993, Millwall relocated to the New Den and ended that season third in Division One, entering the playoffs to try and win a place in the FA Premier League. However, they were eliminated in the playoff semi-finals by Derby County, and the game at the New Den had to be halted twice due to pitch invasions by Millwall hooligans. There was also widespread fighting in the stands.
On 2 May 2002, after the Division One playoffs brought another semi-final exit for Millwall, almost 100 police officers were injured when Millwall hooligans attacked them with missiles in the stadium and in the streets surrounding it. This was one of several major incidents involving Millwall hooligans during the 2001-02 season. On 4 August 2001, just before the season began, Millwall hooligans clashed with those of Tottenham Hotspur outside the Caulkers public house in Bermondsey, in which there were dozens of injuries; the casualties included 30 police officers, three horses and a man who needed treatment for stab wounds. 17 days later, also in London, Millwall fans ran riot in the streets surrounding The Den and caused damage to buildings and vehicles, as well as throwing missiles at police officers after a Football League Cup tie with Cardiff City. Four days afterwards, some 250 Millwall hooligans attacked Burnley fans as they arrived at Bermondsey railway station for a league game. On 31 October, a similar number of Millwall hooligans rampaged in Wolverhampton before a league clash with Wolverhampton Wanderers, which resulted in two Wolves fans suffering facial stab wounds. On 13 December, some 100 Millwall and Portsmouth hooligans clashed at the Windmill public house near Waterloo railway station. Every window in the building was smashed and most of the fixtures and fittings were damaged or destroyed, but all of the hooligans escaped before police could arrest them. On 16 March, Millwall hooligans pelted visiting Sheffield Wednesday fans with bricks and bottles during a league match at The Den; two police officers were hospitalised as a result of the incident.
In February 2011, Millwall fans threw missiles onto the pitch during a Football League Championship fixture against Middlesbrough at the New Den, which almost led to the game being called off. A club spokesman warned in a statement released to the national press that anyone found guilty of involvement in the missile-throwing will be banned from the New Den for life.In October 2004, during a Football League Cup tie at home to Liverpool, Millwall fans taunted their Liverpool counterparts with songs making fun of the Hillsborough disaster which had claimed the lives of 96 Liverpool fans in 1989. This escalated into violent clashes between fans of the two teams. Seven months later, three Liverpool fans received three-month prison sentences and a further two avoided prison sentences but received banning orders. Three Millwall fans received three-month prison sentences and six-year banning orders.