Going back in history, it's possible to imagine digital technologies — from websites to cell phones to Facebook and Twitter — making a real difference. Imagine if these options were available to Soviet dissidents and refuseniks who, back in the 1970s, were limited to secretly communicating by one handwritten samizdat at a time. Maybe the "Iron Curtain" would have come down a decade earlier. Or perhaps the outcome would have been different in Tienanmen Square in 1989 had Chinese protesters been able to communicate and organize instantaneously.
Abraham Cooper on the Facebook blog.