PDNPulse: Mystery: Who Asked Flickr to Delete the Obama Joker?

PDNPulse: Mystery: Who Asked Flickr to Delete the Obama Joker?:

If we rule out Time and DC Comics (both owned by Time Warner), and Platon, who else could have a reasonable copyright claim over Alkhateeb’s image? If someone with no credible case for copyright ownership submitted a takedown request, shouldn’t Flickr have rejected the claim?