A ban on Bitcoin is difficult to enforce
Bitcoin has no centre to attack. There is no single organisation or person that controls Bitcoin and transactions don't go through a central clearing house there is really no way a regulator can stop people from downloading Bitcoin wallets and sending each other bitcoins. If there we to block all the websites that people can download Bitcoin wallets from, new ones will come up and some people will compile their own wallets from source code - Bitcoin is like Bittorrent is that respect. If they shut down the internet, people will send each other Bitcoin via SMS and if they shut down the electricity supply, people will use solar and battery-powered solutions.
But of course it's also likely that a ban on Bitcoin in a country can have a negative effect on adoption in that country.
Technically, sure, banning bitcoin would't have much of an affect, as it would basically be just them saying "your not allowed to". But at that point bitcoin users would become "black market" participants, and there could be a penalty if caught using owning/transacting coins. Yes that would involve open privacy violation but I wouldn't put that past them one bit, I can see bitcoin being the thing to push them past those limits. Most people avoid the black market, too much risk.
Actually bitcoin was created for this, to work ilegally and don't depend of laws because none can control it, the problem about baning is that you can't trade for fiat if you need, so you will have to find a way to spend your coins, a big mess btw...