My banking account can never be seized by a govenment, and I can liquidate them whenever I choose, wherever I choose. Indeed, I can buy a beer with my bitcoin at any time of my choosing.
https://en.wikipedia.org/wiki/Executive_Order_6102
https://en.wikipedia.org/wiki/Civil_forfeiture_in_the_United...
I think when bitcoin is measured in the multi-trillions, the temptation for the US government to raid american bitcoin exchanges will be too great. And they have form.