Just remember, it is impossible for a government or whatever legal authorities to control or ban cryptocurrencies.
Of course not to ban completely, but at least to make it very difficult use.
Actually as far as they will understand that cc leads to collapse of all fiat financial and fiscal systems they will definetly try to do smth like this.
I think, at least in the US, if it goes to the Supreme Court, cryptos will win because the government has declared crypto a property, not a currency/money. I don't think the Supreme Court would say you can't buy and sell property that is legal to own.