Apparently, they are doing this in an attempt to minimize the damage to the company's brand and public image when these videos of brawling mutants are posted online. The last thing McDonalds wants to see is a bunch of animals brawling on the floor with their giant trademark yellow "M" on the wall in the background.
When I lived in Seattle there was a small McDonalds right downtown on 2nd or 3rd ave in the tough part of downtown. It opened at 9am, closed at 3pm, steel gates came down. Lunch only, a Security guard at the door.
A smart owner who just didn’t want to mess with all the crap of downtown when the drinking games began.