make a post on the site that says SNOT! :D
What the forget would that do? The other sites he posted on can be him, it doesn't matter. It's the source of the picture that matters.
Also, saying it's been posted on other sites by you, freckles, isn't proof.
Here's evidence, but not official proof, but it'll convince me; take a picture of your face with Warren's old Meme facial expression. After this, draw me X from Megaman X blasting at the top right corner of the page. Then take a picture with your face in it and the X picture tilted slightly to the left.