It overloaded.

As for shutting things down... Can you throw one switch and kill the web in the US? No. I know there have been attempted to legislate such a thing into being, I don't think they ever passed, and the technical issues would make it hard at best.

Now, can there be a court order served by federal agents ordering ISPs to shut down? Sure. And that would probably work- refuse a court order, the just have the power company turn off your power. The only folks that might not work for are Hughsnet and WildBlue users, but they are statistically insignificant due to their market share (high prices, suck service, low bandwidth- no one uses them who has another option).