Several people have commented that they feel that the required facemasks
have led to an increase in "stickwork".  I've been watching Cornell
hockey for over 20 years, and I really can't agree.  At least in our
league (ECAC), IMHO the introduction of masks did not have that effect.
The effect that it DID have was to very substantially reduce the
number and severity of the injuries from unsportsmanlike moves.  I have
vivid memories of players with fewer teeth after a game than before
and of players returning to the ice with 15 or 20 stiches in their
faces from the pre-mask era.
 
One effect that was quite obvious was a decrease in the number of
gloves off fights, since the wire masks that were most common
cut up the punchers hands!  After a short while, that kind of
fighting just faded out because it git you a penalty without doing
any damage.  Just became sort of pointless.
 
May all be my mind, but I'd say the game is considerably LESS
violent since the masks.