How are they going to ban it? It is international and a independent network.
You would have to shut down the internet.
It would be like banning the $100 bill.
It would be easy to ban it, remember at one time Gold was legal tender and dollar were convertible to gold which was guaranteed by the Breton Wood agreement at the end of WW II..
Just ban the conversion of it to any national currency and ban it as legal tender...if either happens crypto currencies become worthless....
Very few if any countries will allow anything to interfere with or devalue their nation currencies....
Right now Crypto currencies are a blip on the radar of the dollar or any national currency...when and if that ever changes and nations will have no qualms about banning them.
You think the USA will quietly accept any break in the Petro Dollar as a means of international trade....wars will break out before that happens...
Come on you can't be serious? They simply make it illegal to own or trade in cryptocurrencies. NEVER, EVER CONFUSE what you can or may get away with, with what is legal.