China is powerless to stop crypto-currency.
Besides the capital flight via BTC is so damn small so as to be insignificant. The entire market cap of Bitcoin is only a minuscule $12 billion. The daily volume on Bitcoin is $48 million and RNB forex volume is some $5 trillion annually or $14 billion daily. We need a 10 or 100X higher BTC price before we have to worry about it being significant to China's capital flight volumes
It is easier to prevent the decease than cure it, isn't it?
Personally, I think that we need an even higher price than 100X of its current value before it becomes significant as the capital flight volume, but that doesn't in the least prevent the Chinese authorities to treat this issue as potentially important or threatening today. What if they know something that we don't? After all, it will still be the same bitcoins, both by nature and volume, right? But fighting with Bitcoin capital outflows might turn out to be utterly ineffective when the price actually got there while a huge pile of very expensive bitcoins would have had already left China by that time. So why not take precautions now?