It makes a lot of sense when you think about it: CES is full of unreleased gadgets, still waiting on FCC approval, passing their final few safety tests, etc. But China is the Wild West for technology, and manufacturers there don't have to worry as much about, say, whether their new smartphone charger might electrocute people to death. If they can find and copy a great idea at CES, they can have their knockoff on the market before the original even launches.
I first picked up on this at the booth for a company named Onanoff. The company owner, Petur Olafsson, was giving me his standard product pitch when a Chinese man with a camera crept up to the booth and started taking very close-up photos of a speaker case Petur designed for the iPad Air.
"Blasphemy! If your iPad was meant to have a kickstand, God -- er, Steve Jobs would have put one on it!"
Petur got pissed, and shooed this iPhone-wielding James Bond away. He explained that this was not an isolated incident. Similar men had been coming up to his booth all trade-show long, taking detailed pictures and then scampering off, like some kind of weird electronics-based sexual predators. Their badges identified them as "Exhibitors" and not "Press," and none of them ever asked him questions about his mechanical baby. It was clear to Petur that they meant to steal his brainchild.