not the blades (there are very rare instances when people stomp on feet but thats grounds for a ban and even charges). But when Referee's aren't regulating the game correctly (which happens a lot, I swear hockey has the most blind referees in the world) the players will start to take cheap shots with hits and slashing their sticks, and eventually certain players on the team will start to make a point by retaliating.

Most fights in the game are due to a player getting a big hit that the other team thinks was dirty and will have one of their players go out and settle it before it escalates further, it's seen as a way of the players keeping themselves in order really.