China in my opinion can control bitcoin's price, since if all their miners sell at the same time, it would cause a very big dump on bitcoin's price. For now, I think those miners are independent and not controlled by the government. Hope that China won't plan to control bitcoin's price just yet. If they do, they will just need to order their miners and bitcoin users to sell all of their bitcoins at the same time or by banning bitcoin causing the miners to sell at the same time.