Federal and state law both provide a cause of action against inappropriate and unauthorized uses that “tarnish” a trademark. Copyright owners also articulate fears of tarnishing uses of their works in their arguments against fair use and for copyright term extension. The validity of these concerns rests on an empirically testable hypothesis about how consumers respond to inappropriate unauthorized uses of works. In particular, the tarnishment hypothesis assumes that consumers who are exposed to inappropriate uses of works will find the tarnished works less valuable afterwards. This Article presents two novel experimental tests of the tarnishment hypothesis, focusing on unauthorized and unwanted pornographic versions of targeted works. We exposed over one thousand subjects to posters of pornographic versions of popular movies and measured their perceptions of the targeted movies. Our results find little evidence supporting the tarnishment hypothesis. We do, however, find some significant evidence for an alternative “enhancement” hypothesis. Some of our subjects had more favorable attitudes toward the supposedly “tarnished” movies. These results should place the burden on parties asserting tarnishment to prove that it actually exists. In addition, our data support changes to trademark and copyright laws with respect to proof of harm, fair use, and copyright term extension.