The USA should be careful about throwing it's weight around like this too much. Do it too much and the rest of the world will either (a) start using a different .com root server or (b) force the USA to give up power over .com
Cause it hasn't become a big problem yet. The main sites that have been taken down are minority or suspicious sites. Most of the countries that would care enough to do something about this (e.g. Europe) are mostly ideologically similar to USA on a lot of issues. The internet is still so very young, a lot could happen in the next 50 years.
