When Claire and I were in Denver for the wedding of a niece, we joined members of her family for a Colorado Rockies game. Now we love going to a major league game (baseball among all the sports requires one's live presence to truly appreciate it) and we absolutely love Coors Field - clean, attractive, well-designed and with the Front Range as the backdrop for those sitting along the first base line. Very nice.
We also deeply appreciate the fact that Coors Field treats their fans with a greater sensibility to home economy; that is, the Rockies management allows you to bring in a lot more of your own eats than do most of the MLB parks. So, instead of having to hit the ATM in order to purchase $5 Cokes, you can bring your own in -- as long as they come in plastic bottles. The same is true of food items and small thermos bottles. The Rockies want fans in the seats more than they want to gouge you at the concession stand.
Good for them.
But that doesn't mean you can take into the stadium whatever you want and, in a illustration to the absurdly litigious society in which we live, the Rockies feel it necessary to inform you in their official rules what Coors Field will not allow. Among other items, that includes: illegal drugs, glass bottles, aerosol cans, briefcases, camera stands, clubs, fireworks, bullhorns, soap bubbles, animals, skateboards, large squirt guns, fishing poles, laser pointers...and, oh yes, guns and "other weapons."
I particularly love (but remain perplexed by) the fishing pole prohibition.
The full list of what's permitted and what's not permitted (and there's still more curious entries there) can be found in the "Restrictions" section of the Rockies A-Z Guide right here.