The most notable and absolute lifetime ban in the modern history of the National Hockey League was handed down to Billy Coutu in 1927, an unprecedented penalty that stood as a stark warning regarding player conduct on the ice. During Game 4 of the Stanley Cup Finals between the Boston Bruins and the Ottawa Senators, Coutu completely lost his temper, instigating a massive on-ice brawl that spilled over into violent altercations with game officials, specifically physically attacking referee Mick McAtee and linesman Cooper Smeaton. The severity of the assault prompted then-NHL president Frank Calder to take swift, merciless action, suspending Coutu indefinitely from the league. A few months later, the suspension was officially converted into a permanent, lifetime ban from ever playing, coaching, or holding any official capacity within the NHL. Although Coutu later appealed the decision repeatedly over the years, the league maintained its strict stance, and the ban was never lifted, making him the ultimate symbol of zero-tolerance policies regarding violence against officials. While other players over the decades have faced indefinite suspensions or severe expulsions for various infractions—such as severe gambling violations, substance abuse policy breaches, or extreme off-ice criminal conduct—most of those suspensions eventually featured pathways to reinstatement or rehabilitation, leaving Billy Coutu unique in the historical record as the only player definitively handed a literal and permanent lifetime ban for actions directly committed during gameplay.