To use your analogy, the Apple stadium security will probably not let you in if you are visibly carrying pyrotechnics, but if you have a large backpack they are

To use your analogy, the Apple stadium security will probably not let you in if you are visibly carrying pyrotechnics, but if you have a large backpack they aren't likely to look inside. In order to give the illusion that they have good security they also pick many people at random and refuse them entry and make up a reason on the spot.