Your comment should be upvoted to the top. I think the consensus is that they originally came from a porno. The Boston Globe had to apologize for running with them when the story originally aired:

http://www.boston.com/news/globe/editorial_opinion/oped/arti...

You are absolutely right. The images are not of a real rape but a porno one. The fact that the real images haven't been leaked yet is an indication of how protected the troops are, as in "showing this would endanger the troops by making them targets for retaliation". It makes me wonder though, who is making this site writing about the real rape, murder and torture by US soldiers, then attaching fake porno pictures. It's almost as if it deligitimizes the whole story.

No, it's not indication of anything. By default criminal justice system do not publish images of a crime.