bitcoin be controlled by all users. but I was quite concerned with the power of china. china is so extraordinary, they have bitcoin users are very numerous. china can do anything to control the price of bitcoin.
The number of bitcoin users from china is no threat, actually. The threat is that many among the bitcoin users from china are large bitcoin holders. In theory, if bitcoin users from china worked together, they have the power to manipulate bitcoin price by a few dollars up or down by either pumping or dumping their coins.
The millions of traders, many of them in China, who have bet on the price of the virtual currency have kept the cumulative value of all outstanding Bitcoins well above $2 billion since late 2013. At the same time, that speculative activity has left much of the general public wondering why these virtual coins should be worth anything at all.