In North American sport, "running up the score" occurs when a team continues to play in such a way as to score additional points after the outcome of the game is no longer in question and the team is assured of winning. In United States and Canada, it is considered poor sportsmanship to "run up the score" in most circumstances. The term and concept are not common elsewhere in the world.
In ice hockey, complaints are quite rare, for the simple reason that unless there is a gross disparity in skill, teams generally do not score large numbers of goals at will against the opposition. A mercy rule also may come into effect at pre-high school levels, where such disparities might come into play as a matter of course.
However, the rules of competition can sometimes work the opposite direction. In women's hockey at the 2006 Winter Olympics, total goals was one of the factors determining home ice, and so the two favored teams, the United States and Canada, were encouraged to post the highest scores possible. When the Canadians posted a combined 26-0 score in their first two games against the much weaker Italy and Russia, they were criticized in their home country and abroad. However, by the rules, they couldn't let up in case the Americans blew out one of their opponents.