Beijing has set up new restrictions on virtual currencies, trying to curb their exchange for hard items or legal tender. They have banned the trading of virtual currencies, such as the popular QQ coins, for "material products." China is afraid that these virtual economies could destabilize their own currency and markets. This is probably not too far off the mark: what is China to do when a worker can earn more money playing a video game than they can working in a factory?
Oh China...always trying to control the internet...tsk...tsk
As much as China would like to think they can stop this, I believe it is nearly impossible. As long as there are people earning wages in their country generating virtual wealth, it will have a known exchange rate. If there is an exchange rate, there will be exchange.