But at most you can prove which camera shot a picture, and its original owner... Kind of, because there's nothing stopping a photo agency from signing the pictu

But at most you can prove which camera shot a picture, and its original owner... Kind of, because there's nothing stopping a photo agency from signing the pictures after they're taken, in order to anonymize their contributors. So, if I want to fake a picture and make it a bit more convincing, I only need to get my hands on a few cameras from pawn shops in Washington. I just can't say "this is a Reuters photo" or "this is a banned commercial" or whatever.