Does your site suffer from an unseen infestation of sleazy weevils who link to the page decorations you spent hours working on or paid to have created? Does your art show up on their pages and your server do the work of showing your art to their visitors? Hit logs can reveal an infestation. If you see more requests for cowboy.gif than for the page it lives on, you have image parasites.
To cure the infestation, create a 1500x1500 pixel (or larger) image of pure black or white. Make it into a 2-bit GIF so it will be a small file despite its screen-filling size. Rename cowboy.gif to rider.gif and change the page to point to the renamed image. Upload the renamed image and changed page for your customers. Then name the big blank square "cowboy.gif" and upload it over the old image. The parasiteís page will load it instead of the image they originally linked to. Amazing things will happen to their page layout.
Use the tasteless graphic of your choice if you donít like big black squares. I had a persistent parasite who continuously revised her pages to keep using my images until I switched a pretty flower photo she had used on several pages with a large, totally gross-out full-color image from a medical book (oozing lesions on intimate body parts). She complained to my ISPís abuse staff about the content of the graphics on my site. They laughed.
If you donít want to drudge through hit logs searching for parasite tracks, maintain a directory of phony images, named to match your real art in another directory. Periodically create a new directory for your real art and copy the images into it. Change the links on your pages to point to the new directory, and upload the changed pages. Then upload the phony art into the OLD directory, overwriting the real images with their evil twins. If you had any parasites, their pages will be trashed until they notice the problem.