Kate Taylor does an excellent job in the New York Times of laying out the whole story of Jeff Koons’s heavy-handed stance toward a San Francisco store selling balloon dog bookends. Read her story for the full history of Koons’s own defeats for violating the copyright of others. But here, at the very end, is the real story of what’s going on:

William M. Landes, an emeritus professor at the University of Chicago Law School who has written about legal issues involving appropriation art, shared the blogosphere’s view that the business with the bookends made Mr. Koons look a little silly. But he said that artists and their heirs had become much more protective of their copyrights since “the explosion of ancillary merchandise,” including postcards, posters, calendars, umbrellas and coffee mugs sold in museum stores and elsewhere.

Andy Warhol, for example, often used other people’s photographs as sources for his paintings, prompting complaints from several photographers; the disputes were settled out of court. But today the Andy Warhol Foundation for the Visual Arts vigorously protects its copyrights when it comes to commercial merchandise.

In Twist, Jeff Koons Claims Rights to ‘Balloon Dogs’ (New York Times)