Protesters in Zuccotti Park in Lower Manhattan have yet to find an anthem, and some major acts, like U2 and Radiohead, have backed off writing political songs. Some experts are claiming that the nature of protest has changed as well. "In the 1960s music was the social media of the day," said Ralph F. Young, a historian at Temple, who has published a book on dissent in America. "Today protestors have Facebook and Twitter to disseminate their message."