Can dictators use the Internet to stifle freedom?

http://www.wired.com/magazine/2010/12/st_essay_totalitarians/

Debbie Downer, aka Evgeny Morozov, claims that the Internet is a useful tool for dictatorships to maintain control over dissidents.  "Can the Internet empower dissidents and pro-democracy activists? Yes. But it can also strengthen existing dictatorships and facilitate the control of their populations. Washington’s utopian plan to liberate the world one tweet at a time could also turn American innovation into a tool for the world’s subjugation."

Certainly the net can be used to spy on people.  Just look at Facebook.  But the problem with the Internet is that it is ubiquitous. And the problem with Internet Collective Action is that it doesn't rely on particular leaders.  So a dictatorial country or group would pretty much have to pull the plug on the entire Internet if they wanted to stifle any ICA growing up in their domain.  What a dilemma for dictators!