This question was posed by someone particularly interest in the technical computer-nerdy aspects of cryptocurrencies.
'Is it possible for a- government to completely ban Bitcoin? This is an interesting and important topic. The answer is in understanding what Bitcoin really is. A protocol and a language! '
I think he needs to look beyond his laptop to the large angry mob brandishing torches pitchforks and ropes as to the possibility of banning cryptos, especially after larger-scale adoption takes place...