It may be a bit different than outright stealing. Many Chinese businesses make money in a foreign currency outside of China. Instead of bringing the money in and then finding that they can't re-export it they leave it abroad and use it to buy real estate and pretty much anything else they can get their hands on.

This makes for a fairly large but hidden component of the trade imbalance.

The only other way to get funds > $50K out of China is through getting 'permission' which equates giving the right people a cut, or maybe you'll find your money confiscated.

Source: did some business with the Chinese well in excess of that $50k.