Security really depends on the show...i've never stealthed anything there, but I've been to shows with no pat-down, no bag check, and other shows with an extensive pat...also, sometimes they don't allow bags upstairs and make everyone check bags downstairs....ymmv...if you're up in the balcony, i'd say hypers are your best bet...but im sure cards would be fine...hope this helps...what show are you seeing btw??
matt