I think the revolutionary effect you are seeing can be better attributed to the fact that these populations have access to the Internet, especially through mobile phone. These people aren't leveraging the unique features of social media (the web of interpersonal relationships) so much as they are leveraging the ability to quickly get text, pictures, and video out of the country and onto servers hosted in countries sympathetic to the protestors. It just happens that Twitter and Facebook are currently the fastest ways to get something published and seen.
I disagree - because the ability to get text pictures and video out of the country reliese on the fact you're putting it onto a network where plenty of people are linked together. Just posting it onto the internet - with no social network apps - it's much less likely to catch and go viral.
The networking capabilities of these appliations is what makes them useful to protesting organisations. Otherwise there woudl be a deluge of emails going out to notify of each individual update - rather than a simple, distributed notification which people can jump on at any point.
