The US has always advocated free speech, and the internet has become a forum for various ideas, to the extent that it is behind the revolutions in Russia, China and Middle Eastern countries such as Egypt. But since Congress agreed to give the military power to conduct "offensive" clandestine strikes online, they may be targeting US.
This 2012 bill has done some good things so far: In Wired.com, Ryan Singel writes that: "While ‘offensive’ action isn’t defined, that’s likely to include things like unleashing a worm like the Stuxnet worm that damaged Iran’s nuclear centrifuges, hacking into another country’s power grid to bring it down, disabling websites via denial-of-service attacks, or as the CIA has already done with some collateral damage, hacking into a forum where would-be terrorists meet in order to permanently disable it."
So far, despite rumors, there’s no documented of military hacking attacks on US internet sites. But with new technology, it could happen–if someone in the government doesn’t like what we’re writing about.