Violence has been a part of ice hockey since at least the early 1900s. According to the book Hockey: A People's History, in 1904 alone, four players were killed during hockey games from the frequent brawls and violent stickwork. More modern examples of violence include brawls, bench clearing brawls, fighting, fan involvement, physical abuse of officials and deliberately injuring opponents. Violent actions such as kicking, hitting from behind and prohibited stickwork, are penalized with suspensions or fines. Fighting, or fisticuffs, is also penalized but is considered by many hockey enthusiasts, particularly in North America, to be quite distinct from stick-swinging or other violent acts. They regard fighting as an entrenched, acceptable and integral part of the game. On the ice, referees may impose penalties for prohibited activities. Off the ice, the National Hockey League (NHL) sometimes fines, suspends or expels players. The criminal justice system has also occasionally charged and convicted players. As a result, hockey has become much more regulated and the violent element much more controlled. This has been aided, in no small part, by dramatic increases in disciplinary processes and technology allowing for a high level of scrutiny of any event which occurs. History Early hockey in particular was noted for its extreme violence, to the point where two players were killed in three years during brawls. In both cases, the accused assailants were acquitted, but these and other bloody incidents led to calls for the sport to clean up its act or be banned along with the likes of cockfighting. The worst of the violence waned, particularly with the advent of regulations for quasi-legal fisticuffs, though incidents continue to occur from time to time. Cully Wilson, right winger with the Seattle Metropolitans, slashed Vancouver Millionaires center Mickey MacKay over the mouth during the 1919 PCHA season. MacKay suffered a fractured jaw and missed the rest of the season. When the season was over PCHA chief disciplinarian Frank Patrick banned Wilson from the league, and Wilson never played in the PCHA again. Billy Coutu was the first, and to date only, player banned from the NHL for life for violence in 1927; he assaulted referee Jerry Laflamme and tackled referee Billy Bell before starting a bench-clearing brawl during a Stanley Cup game between the Boston Bruins and Ottawa Senators, apparently on the orders of Bruins Head Coach Art Ross. The NHL's first president, Frank Calder, expelled Coutu