I remember how shocked I was to discover, during my first trip to the Yankee Stadium bleachers, that there was no beer allowed in my section. Gah!
Now the Seattle Mariners are rolling out no-nut seating, so that people with nut allergies (12 million and growing) can come to the game at (appropriately named) Safeco Field without fear of imminent death. That means no Cracker Jack, too. (Mmmmm, Cracker Jack...)