I guess the question is, why do you want to bring the iPad into the stadium? I have seen people using iPads as cameras at arenas before, but they're not the best.
I've tried taking an SLR into arenas with varying degrees of success. A few years back, I brought my Canon DSLR with a small camera bag into the Air Canada Centre in Toronto for WWE Smackdown with no issues, until I put on the telephoto lens. That's when security came up to me and told me "professional cameras" weren't allowed, and I had to take the camera to the coat check area.
After that, I've managed to bring in my Sony NEX-6 with the 50 mm lens. Security thinks its a point and shoot, so they leave me alone. If I have seats in the first or second row, it works great!