Easily be stopped? Hardly. You have to realize that the government is slow to react. Even if the US outlaws bitcoins or another countries does then there are still 200+ other countries where it is legal.
Easily. If there is one persistent fallacy that is repeated over and over again on these forums, that needs to be put to rest it's this "Bitcoin is unstoppable" and "we don't need anyone" foolishness. The Developers don't think it's unstoppable- and they know the code back to front.
...[redacted truth for brevity]
So can it with the "unsinkable ship" "they can't stop us" talk. Yes. They. Can. That does not mean they will- but it's pure hubris of the most ignorant sort to think it can't.
Everything in that post is right on the mark. It should be posted as a sticky. New members should have to read it and sign it like a microsoft license agreement.