What sort of rubbish? When did the Americans banned cryptocurrency? In fact many of the earliest cryptocurrency exchanges are based in the United States. On the other hand, there is a fiat ban on cryptocurrencies in China and direct fiat to cryptocurrency trading is not possible there. And that is the reason why a lot of Chinese users depend upon exchanges in Hong Kong and South Korea. But in the United States, the exchanges don't face any sort of restrictions (in any of the states).