The study, to be published this month in the Bulletin of Sociological Methodology, came about when French sociologist Antonio Casilli and his colleague Paola Tubaro noticed that the same media said to convey democracy in North African countries was blamed for channeling anarchy in Westernized ones. Geopolitics and human-rights issues aside, they wondered, what effects did social media actually have on public violence?

Casilli and Tubaro used computer modeling to try and answer the question. The idea, basically: use real-world data from situations of civil unrest to create rules about how people in those scenarios behave, enter those rules into a computer, and then see how your computer populace behaves under conditions of your choosing. Casilli and Tubaro simulated the potential effects of censorship by playing with a variable called "vision" — awareness of social and spatial surroundings during a riot. High vision corresponds with low censorship, and low vision with high censorship. Think about vision geographically: If a citizen has a vision of diameter of one mile, that means they can only see their immediate surroundings. But social media can drastically increase the diameter of vision — citizens can be aware of what happens one, five or 50 miles from their location. During a riot, this can help people decide whether to converge to another neighborhood, to attack a target or to help others resist police.

The model showed that high-vision situations without censorship still featured sharp peaks of violence, but these were followed by longer periods of social calm than low-vision scenarios. The researchers speculated that these calmer periods might be due to the fact that citizens who are more aware of their situation are more likely to initiate positive civic action than those who are left in the dark. "In the case of the London riots, people living in different areas of the city were able to get in touch and communicate [through social media]," Paola Tubaro told me. "That was both active protesters triggering others, but also people getting together to put things to rest, clean up the mess and bring the community back to normalcy."