The entire reason acts like the PROTECT IP act even get this far is because NO ONE understands the internet, and the potential of it.
Yeah, we're slightly more enlightened than the politicians, but that's not really saying much.
All we know is that it'd be better to just leave the internet alone for now, until we have a better idea of its potential (which, I acknowledge, may never happen).
Of course, as other commenters have said, the idea that the US can basically say "follow our law, or you have no internet" is disgusting. Unfortunately, this threat will hold until some country decides to call the US's bluff.