"If you care about social change, this may well be the most important 'art history' book that you will ever read." --The Yes Men, art activists Drawn from an exhibition at Exit Art, a cultural center in New York City, Signs of Change is a visual archive of more than 350 posters, prints, photographs, films, videos, music, and ephemera from more than twenty-five nations. Surveying the creative work of dozens of international social...