But the artist Jeff Koons, who constructed a 10-foot tall “Balloon Dog” that has been exhibited in the Metropolitan Museum of Art and elsewhere, sent a cease-and-desist letter to a Canadian manufacturer and San Francisco gallery for producing and selling “Balloon Dog” bookends. Now the gallery, Park Life, has asked a federal court for a declaratory judgment that states the canine shape cannot be copyrighted, according to Courthouse News Service. “As virtually any clown can attest, no one owns the idea of making a balloon dog, and the shape created by twisting a balloon into a dog-like form is part of the public domain,” the gallery says in its federal complaint.