The governments can't control Bitcoin because it is decentralized. It wasn't made in favour of a centralized system where one person or authority can have full power and control over its transaction. The farthest the governments can go is to impose regulations on Bitcoin transactions especially on the exchange sites.
bitcoin is free in the market. the government will not be able to control bitcoin, because bitcoin is not a product of a country and is approved by many countries. even if it makes rules about bitcoin, the government cannot implement it according to the rules it must still be in a reasonable stage.
bitcoin is present in the world for the trading system, and it is entering the free market. anyone can trade and use it