I agree with this, Altho Bolivia Has done it, But how can any government say you can not "use" bitcoin, Bitcoin at the moment is not seen as a currency in the eyes of the law, it is being seen as property and even being taxed as such in some places right now, Therefore, you can not make laws that tell people they can not use it for trading/bartering. In a sense they would have to stop all things that are traded from one thing to another, Like craiglist ads that say will trade my crappy truck for your nice ATV OBO, exactly the same as trading Litecoins for Bitcoins or trading Bitcoins for US dollars. I mean things like this are done everywhere with other pieces of property, if not for this form of bartering Ebay would not exist, ebay even takes it a step farther where it allows people to compete for the highest price in order to trade their local currency for items they see that they want.

I think in most civilized countries these laws will not and could not hold up in any court of law without pressing farther restrictions on other things being traded.