Photo: Sakurai Midori, Wikimedia Commons , CC BY 2.5 In 2011, the British wildlife photographer David Slater travelled to the Indonesian island of Sulawesi to photograph crested macaques, a critically endangered species of black tuft-headed monkey found in the forests of the island's north. The United States Court of Appeals for the Ninth Circuit later took as its starting point the version of events in which Slater left his camera unattended in the reserve and a macaque picked it up and took a series of self-portraits. One, a close-up of a grinning face looking directly into the lens, became one of the most widely shared wildlife images of the decade. Slater has himself given different accounts of how much he staged the shot, at times describing a remotely triggered camera on a tripod that he set up after days of winning the troop's trust. Those details might seem incidental, yet they were at the heart of a question no copyright statute had been written to answer, namely wheth...