British Prime Minister David Cameron says his government will look into a possible crackdown on social media, after citizens used websites like Twitter as an organizing tool for the riots that shook cities across the U.K. earlier this week. Free speech advocates have criticized the idea, saying it's reminiscent of the social media shutdowns practiced by autocrats like former Egyptian President Hosni Mubarak. Are Cameron and Mubarak suddenly brothers in censorship? Or is this a viable method for preventing violence? We're speaking with Jeff Jarvis, a journalism professor at the City University of New York, and the author of the upcoming book "Public Parts: How Sharing in the Digital Age Improves the Way We Work and Live."