From the just-out press release about tomorrow night's show at the Tacoma Dome (visual enhancements added):

Costumes are welcome; however, anything resembling a weapon (whether part of a costume or not) will not be allowed into the venue. Aluminum cans used as part of a costume must be empty. Be kind to your fellow little monsters—don't wear a costume that will endanger others!

Was that "cans must be empty" decree necessitated by stupid kids trying to wear full cans of Pepsi on their heads, or smart kids trying to sneak thrifty soda/illicit booze into the show? Weigh in on Line Out.