they can do it but they wont do it. in my opinion, the gov looks this tech is what they need in the many future ahead. which everything needs an upgrade and its more efficient to use. but if they do get law against btc, it means that they fail to get profit from it. any gov is just trying to set up how to getting profit from it in a long period time. if all country have their own crypto signature and yet its can be use anywhere in the world its actually more profitable to everyone if they looking deep into it. PROFIT all the time, anytime, anywhere, and everyone.