Here in my country national banks accepted the use of Bitcoin but they regulated exchanges for anti money laundering or use of any illegal activities. Just don't be scared because there are ways you can still use it even they prohibit the trade of Bitcoins in your country. You might use vpn's or tunneling connections. If all countries arround the world prohibit the use of internet then I can say that it's kinda scary but it is impossible to happen. Well for me yes there is a small chances that Bitcoin will be prohibited in every single country but not to the extent of having a total ban because people can still find ways to use it like  underground trading.