Originally Posted by Magnetron

In a situation involving Hotlink protection that redirects to a page rather than an image - Google attempts to load full size images for surfers, causing that page to sort of get pinged without an actual visitation and the page owner gets credit for the search.

When an asshat webmaster Hotlinks to your images and attaches his own descriptions, Google indexes it and you get credit for irrelevant search terms again from Google giving away full size image loads.

Hotlinking on top of Hotlinking.