To play a slightly comical devil's advocate, what if Neil Armstrong had intentionally angled the camera down to avoid photographing their flying saucer escort? From the original it's not obvious that the area above Buzz Aldrin's helmet is black.

Yes, I know, it is really, but you don't know that from the photo, and that's an important distinction when you don't know the full context your reporting of the photo will be presented in at a future date. I think the argument is that crops and rotations are generally ok (although the argument about the upside-down footprint is interesting), but a transformation which claims to add information not originally in the photo cannot be ok.

Even a simple crop can make a large effect: http://www.abovetopsecret.com/forum/thread545972/pg1