Lots of shit gets stolen. You just really need to keep an eye on where your shit is though. I let my stick be used by about 5-6 people at NEC, and since i was sitting there watching the matches, it wasn't a problem. If a motherfucker needed it for another game, i would have declined.
Also, if you bring setups, keep an eye on those too, even though its hard to get away with im sure people have stolen them too.