Hey, if you guys want to wear bags, you just gotta fold them up and put them in your pocket when you enter the stadium. Also, be prepared to be kicked out once you begin wearing them. But, if that happens, make the biggest scene possible!
Makes me think of a funny thought I had before:
Wear a replica referee's uniform to the game and bring a lot of yellow penalty flags with a little sand in them. Then, at some point during the game -- like when Hall whiffed or we got the safety -- start throwing them out onto the field like a madman. Also, and this is really important, make sure you get hammered beforehand. Let me know how it goes!