in the nhl fighting is part of the game. it really is just frustration taking over.  it's not really aggression.  in reality, many of the players are friends off ice and foes on ice. it is just for fan base. but there have been some justifible fights like the march 2001 incident at the joe louis arena when darren mccarty of the wings and claude lemieux of the colorado avalanche fought. they fought becuz of morals.  lemieux gave a dirty hit in the playoffs the year before that caused a broken jaw to kris draper(another wing) and mccarty was paying him back.  it was a great fight.  it can also make a game exciting. as far as the olympics i'm not sure if they fight.  in junior they have less fights. they focus more on skill. in beer leagues they fight for all reasons. i don't mind it. it does not make the sport of hockey violent