Brad Marchand of the Boston Bruins has a disciplinary hearing with the NHLfor this hit on R.J. Umberger in last night game against the Columbus Blue Jackets. In my opinion it's a violation of rule 48 and worthy of a suspension from the NHL.
48.1 Illegal Check to the Head – A lateral or blind side hit to an opponent where the head is targeted and/or the principal point of contact is not permitted.