The Fourth International Seminar in Network Theory, sponsored by ANN and the Science of Networks in Communities (SONIC) research laboratory at Northwestern University, was held at the University of Southern California April 26 – 28, 2012. The conference theme this year was “Networked Social Movements and Network Theory,” and speakers included Sasha Costanza-Chock, Karine Nahon, Steven Livingston, Mario Diani, Gilad Lotan, Lance Bennett, Richard Rogers, Michael Macy, and Manuel Castells. For more information about the conference, video of the speakers, and presentation summaries, see the 2012 conference page on our website.