The subject already gives a hint for the idea I had. But let me explain a bit further. Maybe someone has a better idea?
A friend of mine has a homepage where she presents some photos. She already password protected that realm on the server (.htaccess) but still some unfriendly users spread her pictures on the net.
My idea is to code into the picture the name of the user who loaded it. Can anyone recommend perl librarys being able to do that? Or has anyone of you a better idea to find out who spreads the pictures?