Young one, they used to let you bring whatever you want into the stadiums. Oh how I miss bringing in my hart's 64oz full of diet coke into cougar stadium. (It wasn't called LES back then
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Folks could bring whatever they wanted into the Ute stadium and they did indeed waste their beer from time to time. So maybe you can call bs on anyone saying they did it currently, but I know for a fact it has happened in the past. I've seen it.