Yes, it is ridiculous the lengths to which some people will go. I've had success using the Internet Wayback Machine to stomp on them.

On Wed, Apr 2, 2008 at 1:48 AM, Bryan Tong Minh <bryan.tongminh@gmail.com> wrote:
Screenshots are as much fakeable as everything else. In fact we once
had a user who "proved" that an image was free by sending a fake
screenshot.

Bryan