The case is Warner Bros. Entertainment, Inc., et. al. v. X One X Productions, A.V.E.L.A., Inc., et al., 644 F.3d 584 (8th Cir. 2011). Defendants obtained old movie publicity materials - posters and lobby cards - took images of famous characters from the materials, and licensed the images for use on apparel and other goods. The promotional items were not protected by copyright (but the films were, of course) - the court found they were in the public domain. However, when the images displayed on the licensed merchandise evoked the film character, the court found infringement. Here's a link to the story.