This will be their main concern in the BTC arena.

We need to remember that they are also bound by the laws of the US and they can't barge into a business premises and close them down without serious evidence or serious criminality. They do not want to be taken to court for a multi-million dollar law-suit, which is what they would face if they closed down any legitimate business that is serving it's customers and investors well. If they have issues then a company is wise to follow their advice or instruction but so far they have decided to guide the industry down he right path rather than kill it. Bitcoin will create tens of thousands of jobs in the US, if Ken and others don't do this business in the US then the Chinese will simply steal the share of the market. That's not good for the US economy or US investors.