I don't think someone controlling the Bitcoins maybe the exchange/price can be controlled by the Chinese who are the majority of miners of Bitcoin but I think people are smart to know how to join the wave of it when the price goes low or high. If however, some group will control bitcoin we will know it for sure.
I agree,BTC isn't controlled by anyone,stop thinking that there is someone actually controlling it,yes,China has a lot of miners who are holders of BTC as well but that doesn't mean that they are in control because the demand is really high and BTC is always in circulation,it's hard to control BTC unless you have a really big share of it which is in the hands of a couple of people or organizations.That's when the control can be made but that's not the case so relax.