Its a big risk for the government since bitcoin provides all improvement for the help of the entire humanity. If they banned bitcoin, they make a way to refuse the opportunity that will improve the society in future and well civilize.
IF bitcoin is banned many people will lost job, in fact many people will lost their life standard because they are working hard with bitcoin and earning well from bitcoin and thus they maintain a life standard. Many people will End their education because many student are working with bitcoin and earning from bitcoin and in this way they continue their education. In fact the over all world will be affected. But it is no possible to bane bitcoin if government banned people will use the bitcoin illegal.