Portland was Washington's affiliate, but the Caps recently changed to Hershey. Philly at one time had the Bears, but they now have the Phantoms. I suspect the Portland folks are pissed that the Caps left them for Hershey. This happens all the time... not sure why they would take it out on the players. I didn't see the game, so I'm not sure if a particular incident kicked this off.
When the team with the best offense in the league gets spanked 5-0, there's gonna be fights. ;^)