Thus, claims of communication technologies as the primary cause -- or even the catalyst -- of large-scale positive social change are misleading, and they lead to poor policy in foreign affairs and international development. They commit the classic error of confusing correlation with cause. It's not so much that tweeting foments rebellion, but that in our age, all rebellions are tweeted.
What, then, is the cause? Three points emerging from Egypt and Tunisia offer clues. First, the protesters express years, if not decades, of frustrations with their government. People need to be deeply unhappy before they march. Second, the protests are led mostly by educated, middle-class people. It takes an educated population that isn't living hand-to-mouth to risk an upending of the status quo. In contrast, there are many oppressed but starving populations that don't put up a fight. You can't eat freedom; better a dictator who feeds you than a democracy who doesn't. Third, the governments' physical might, or their will to use it, appears to be weak (though Mubarak has yet to show his cards).
Technology magnifies the underlying intent and capacity of people and institutions. But it doesn't in and of itself change human intent, which evolves through non-technological social forces. (Witness how no amount of FoxNews and MSNBC converts opposing opinions; if anything, they polarize.) Successful revolutions are tipping points, which mark the point when the power of capable citizens frustrated with their governments exceeds the will and physical might of a government intent on power. An avalanche's underlying cause is a flake-by-flake accumulation of snow; similarly, the tipping point of revolution is the culmination of a person-by-person accumulation of frustration and middle-class security.
Technology can communicate and spread frustration, but it also amplifies government propaganda and misinformation. Technology can accelerate a revolution once it begins, but it can't feed or educate an enfeebled population to the point of rebellion (PCs for schools notwithstanding).
What does this mean for policy? Technology policy should be more selectively applied. It helps most when the social balance is already in favor of a desired outcome. Otherwise, there are other conditions we might push for first -- good nutrition, viable healthcare, and universal education -- most of which are less controversial, even for dictators. And, in any case, technology-for-all policies require extreme care, as Hillary Clinton found with WikiLeaks and "Internet freedom," technology's blade is always double-edged.