These images became public-domain material the moment the macaque generated them. Caters licensed the rights to exclusive use of them from Slater, but then faced a conundrum: How could they exercise those rights? Only by maintaining strict control over their availability. (For example, if they’d licensed reproduction rights to a T-shirt manufacturer.) As soon as the agency released digital files of the images for distribution via an online publication, the Daily Mail, their public-domain status became activated, so to speak. […]