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.
Regulations is the closest they can do because they will have to spend a lot of money and a lot of manpower if they try to control Bitcoin transactions or if they will try to ban people will always find a way use transact and store their Bitcoin in fact they can benefit if they allow it and then just charge taxes on services and products associated with Cryptocurrency.