You may be familiar with the Palin’s-head-on-someone-else’s-bikini-wearing-body Photoshopped image. I’m not sure of its actual provenance, but since I’m only using it as an example of my question, assume for the moment that it was done for commercial purposes, and was done by a non-affiliated person (i.e., not part of any news, political organization, group, etc.).
As a celebrity/politician, it’s probably safe to say that use of Palin’s image falls under fair use. But what about the girl in the bikini? Could she have a reasonable claim against the Photoshopper? What about the original photographer? Would it make a difference if the photographer was an amateur who posted to Flick’r or a professional photographer who was otherwise selling the image? What about future use of the image? That is, now that the original photograph has gained some notoriety (and assuming it’s use was unlawful in the first place), could a subsequent work using it as a parody of the initial coverage — such as pasting the World Trade Center tourist — fall under fair use?
Sorry to use a political example, but it’s how the question came up. Feel free to tweak the conditions, assumptions, and example as needed to answer variations on the theme.