IF the whole world ban BTC at first BTC will Crash very hard but only for a few month, Demand will be increased while there will be no Legal Seller, All trade will go to undergrand and Black market and illegal traffic, sellers will start to selling BTC 50 X more than current price. BTC will be more expensive, As simple as that,
That was an answer for these who said BTC will die if whole world Ban it, So no BTC never Die.
The moment that worldwide government ban bitcoin, then bitcoin is already gone, only few people will be bold enough to start using it and they will not be encouraged because there will be very little or no volume to carry make their trading transaction successful.
It would even be very impossible for bitcoin to be banned now because out of many nations of the world, there are several ones that have already adopted the use of cryptocurrency already and are already benefiting from it which will make it difficult for anyone to actually change their mindset or stop them from using it and even if the United states is against it, those government would still be able to use it because they have their own power and control themselves to do what will benefit their country and their economy.