Originally posted by the Voice of America. Voice of America content is produced by the Voice of America, a United States federal government-sponsored entity, and is in the public domain. The Future of Protest? Catalans Outwit Spanish Authorities With Phone App Henry Ridgwell LONDON - A pro-independence group in Spain's Catalonia region is using a smartphone app to outwit authorities, as it steps up demonstrations following the jailing of several of the movement's leaders. The group Democratic Tsunami released the app to coordinate demonstrations across the region. The latest target was the world-famous El Clasico soccer match between Barcelona and Real Madrid on Dec. 18. There were violent clashes outside the stadium, and protesters disrupted the game by throwing balls bearing pro-independence slogans onto the field. Democratic Tsunami has no apparent leader and those behind it are anonymous. In recent weeks, the group has mobilized thousands of demonstrators in minutes, catching authorities by surprise. WATCH: Henry Ridgwell's video report .