On May 15th of 2011, thousands of activists and sympathizers gathered at Puerta del Sol, one of the best known and busiest places in the city of Madrid, to protest and demand solutions to rising unemployment and other symptoms of the ongoing economic crisis in Spain. They were joined by tens of thousands of protesters who demonstrated in streets and public spaces across Madrid, Barcelona and several other Spanish cities. In what became known as the Indignados or 15M (short for May 15th) Movement, participants initiated experimental workshops in participatory democracy that often resulted in rejection of the existing political system, capitalism, banks, and corruption. They also called for an expansion of basic citizen rights to include home, work, culture, health and education. Even though the movement eventually subsided, it had a profound impact in Spanish politics and society, as well as on movements in other parts of the world that were inspired by it. The materials comprising Princeton University Library’s collection were gathered in 2011, during the protests, by a participant with whom the library partnered to document the movement.