That is the great thing about bitcoin. It is a decentralized P2P network. It would be like the government trying to "stop" Kazaa, Napster, Torrents, Newsgroups, IRC, any other file sharing network. They can only work in their jurisdiction. And they can only "block" so much of the internet usually things pertaining to copyright. You can even still download Kazaaa Lite I think if you really want to today? In the case of bitcoin, it is not even sharing copyrighted material. It has been discussed on news outlets with minimal disdain, discounting corrupt governers or politicians that in my opinion can blow a sack of you know what anyway. It was even on foxnews recently, with jon stossel who seemed to be in favor of the coin.
What it comes down to is, bitcoin is not illegal, it is an online currency. It honestly has about as much merit as facebook coins and pogo bucks. The part the government doesn't like about it is the face value, they have no control of it, and they think it devalues the U.S. Dollar. (There is other issues as well such as the black market, but I mean come on, countries are the ones who created "cash" in the first place, the main source of currency in the black market globally. Not many c*ke dealers accepting visa. Yet they endorse U.S. dollar like its gold.) Another thin is and may become more is popularity, which again rises and falls with any type of currency from ANYWHERE in the world. In fact, just like any other currency, it supports economies, and can be converted to almost any currency just like ANY other country. It is rising in popularity and success, and I must say it is quite impressive.
And While I do see some problems with bitcoin, I do not see the U.S. government shutting it down becoming an issue. I say stock up know as much extra as you can afford or now. And if you were super early adopter GL!!