It's not possible to stop Bitcoin just by making it illegal.
Totally disagree.
If the governments makes bitcoin illegal, all the exchanges will have to go bye bye. This means that bitcoin will lose mainstream adoption, and also make it a lot harder for the underground bitcoin people to operate, because at the end of the day they really need to change their BTC into cash if they want to buy anything legal... Right?
Nonsense!
Silk road is a great example of illegal things being bought and sold!
More importantly, the example of mass shooting with illegal weapons by illegal users is key in demonstrating that illegal status makes no difference
.
Enforcement of illegal things is the key, and most governments know, most people are self enforcing. If people refuse to stop using Bitcoins, it's going to take more actions by governments to kill it.
It's not about illegal things being bought and sold, it's about the value add of bitcoin.
Individuals can easily refuse to stop using Bitcoin, but the companies which make bitcoin valuable can't. Mt Gox and the other exchanges bank accounts could be instantly frozen, and overnight bitcoin has a huge problem about buying and selling the currency that realistically couldn't be overcome.
Furthermore,
1. If bitcoin was illegal, then the majority of the people currently buying it would't be able to, and would no longer be interested.
2. With only underground exchanges left, there would be a massive oversupply of coins and the price of bitcoin would plummet through the floor.
3. Because the price is so low few people would be interested in mining.
4. Because so few people are mining, the network becomes open to 51% attacks
5. Nobody trusts the currency, and people revert to existing channels of trade.
5. Game over for bitcoin.