At the early stages Russia ruled it as illegal, China outlawed all withdrawals and some other country also spoke against it. But now everything seem to be smoothing up at least on the government side. Surely Bitcoin must be seen as challenging their authority. Is there something I am failing to see? All it would take is a 51% attack or a new law.
Although the government can ban the use of Bitcoin the government will not be able to stop Bitcoin. Because Bitcoin is a cryptocurrency in which there are sophisticated technologies that can not be stopped.