Welcome to WebmasterWorld Guest from 188.8.131.52
Forum Moderators: phranque
Best you can do is try one of the following:
Move your graphics directory once a month and in the old directory leave an htaccess that leds to banner ads. Or leave a graphic with your domain name in the old location - they'll get tired of advertising for you.
Personalize your graphics (notice the name in the top left logo here now? that's why)