Get few of them, borrow to neighbouring stands, charging fairly for data usage, sell them after event. Congratulations - you just made few friends, some good karma and flipped off convention organizers, all at the same time.
Given the shitstorm they threw when they caught me carring a small mat to my booth (turns out I need to pay $100 and wait an hour for one of them to carry it), I can imagine what they'd do if they found cables between booths...