Facebook and twitter came at a pivotal time in history. The chicken or the egg theory can be applied here in asking: Did twitter and facebook help revolutions grow, or did they help track people involved in uprisings? (In both the case of the Arab uprisings and the Occupy movement.) I would say both.
Kofi Annan's initiative is in trouble. The Syrian regime declared its acceptance of the UN sponsored plan on March 27th 2012. The main requirement of the plan is the pulling back of the Syrian troops from Syrian cities by April 10th and all fighting to stop within 48 hours after that.. There is no chance of that.