Image Hijacking

I've been tracking down quite a few image hijackers recently. These unscrupulous people choose to host web pages and use the images from another's webserver (in this case mine) for their site. Nevermind that they would probably never think to even ask for permission to use copyrighted images, but they go one step further. In the process of stealing my work they use my server to do it. Well, they did. No more. The really bad thing about it is that by doing this you're allowing someone else (me) to control what happens when people come to your site.