Wikipedia
Cross-checking is an infraction in the sport of ice hockey where a player checks an opponent by using the shaft of his or her stick with both hands. In the rules of the National Hockey League, cross-checking is defined in Rule 59.
While body checking is allowed, the use of the stick increases the risk of injury to an opponent. The most common penalty is a two-minute minor, served by the offender. However under certain circumstances the referee may assess a major penalty (plus automatic Game Misconduct) or a Match Penalty if the action is judged to be an attempt to injure the player. Usually, if the cross-check causes an injury the league itself may look into whether or not extra punishment is required for the player that delivered the check.
International ice hockey rules and league rules though slightly different lay out the foundation of penalties for cross-checking. While the differences happen to be subtle in the context of international hockey events such as the Winter Olympics and the World Ice Hockey Championships, the penalties tend to be stricter than those from the NHL, KHL and the minor leagues. Most of the time the severity of the penalty depends on what the referee's judge to be the severity and the intent of the cross-check. The penalty is generally assessed by the referee that is on ice and is up to their judgment to decide whether the penalty was a cross-check or something else. For example, at the 2014 Sochi Olympics Women's Gold Medal Game between Canada and USA, Hilary Knight of the USA team was assessed a cross-checking penalty on Canada forward Hayley Wickenheiser. The call caused uproar from both benches, while the Canada bench thought it was tripping and there should have been a penalty shot, the USA bench felt that it was not a cross check. The discretion of the referee decides whether or not a cross-check is to be called.