Governments should ask themselves the question whether they want cryptocurrency to be underground or not. Whether or not you regulate / ban something people want or need, they will get it.
Unfortunately, most of them can't understand yet that it is not possible to regulate bitcoin. If it is somehow possible, this 'regulation' will have nothing in common with the way legacy finance/banking system is regulated. Money will be separated from state. This separation won't be less violent than separation of state from church 5-6 centuries ago.