Of course they can. They can always come up with laws restricting the usage or the operations of exchanges, however, there will always be a way to trade, it's just a matter of badassery. 
Bitcoin is not so different from amphetamines, the government can always regulate but the trade can happen with them unaware. Law of supply and demand, dude.
This guy gets it. You can hide your cryptos but you're at risk on exchanges.Bitcoin is not so different from amphetamines, the government can always regulate but the trade can happen with them unaware. Law of supply and demand, dude.
Maybe sometime in the future when authurities can already figure out as what policies and laws are appropriate to cryptocurrencies. This would be advantegeous to us bitcoiners to prevent fraud and criminalities worldwide.