If they don't matter, neither does a watermark.

and you need the watermark to tell you the fish with the mustache is fake...

What image is going to change your worldview so radically that the drm saves you?

edit - to be clear you are watermarking 100,000 fishes with mustaches because of your concern over 1 image that "matters" (and you don't even have an image that matters in mind)