You don't need to live in a totalitarian and communist regime to experience banning of something. In EU for example, laws have been voted to ban glyphosate (Monsanto Roundup) use for example. In some countries of the free world some gov's plan to make the use of a bicycle with helmet illegal so why not BTC ? If a government judges it as a tool for money laundering they can decide to vote a law to make its use illegal.