Should the government be allowed to shut down websites they consider to be supporting terrorism, Wikileaks...?

The first three responders have good points - especially a sentence by JK47. Flimsy excuses to bring in laws for other purposes. The Obama administration spoke of the "Fairness Doctrine" for 2 years. This was a "flimsy" attempt to eliminate opposition voices that were speaking on the constitutionality of some of Obama's bills. You can see here the easy jump it would be to silence opposing voices under the guise of security. So I think the Net should belong to the public.