The associated press alleged copyright infringement for the use of one of their photos in creating the Obama campaign poster. Fair use is an exception to copyright infringement. To determine whether a work falls under the exception the court looks at factors such as how much of the original is used, what the new work is used for and how the original is affected by the new work.
Fairey found the photograph using Google Images. He released the image on his Web site shortly after he created it, in early 2008, and made thousands of posters for the street.
I feel like what he did was fair use as user generated content. The picture was changed and sufficiently given artistic expression. Plus, I agree with Mannie Garcia who claims that his contract with AP says that he owns the copyright for the photo not AP. Mr. Garcia said, "If you put all the legal stuff away, I’m so proud of the photograph and that Fairey did what he did artistically with it, and the effect it’s had.”