Art made to attach to buildings or to be given away? Wearable art for street demonstrations or art that sets up a booth at a trade show? This is the art of the interventionists, who trespass into the everyday world to raise our awareness of injustice and other social problems. These artists don't preach or proselytize; they give us the tools to form our own opinions and create our own political actions. The Interventionists, which accompanies an exhibit...