A similar thing happened to Microsoft ten years back, when they hotlinked to an image on flickr and violated the CC licensing by doing so. The owner of the image swapped out his original image at the link, replacing it with the infamous goatse image, which appeared on Microsoft's site for some period of time.
The image owner wrote it up on his blog. You don't really need to follow links to the goatse image or a screenshot of the Microsoft page displaying the image, but they are there: http://www.niallkennedy.com/blog/2006/12/microsoft-copyright...