the only way to protect images against the "print screen" attack is to overlay it. overlaying is a technique used in video hardware playback that paste an image over the "video output" of windows (now computer freaks will kill me: it's just to explain). for example in winamp AVS you can overlay (if your HW supports it) the avs output on the desktop. if you try to print-screen it you get your desktop with a flat black bg. but the only way to implement it is to write a java applet that does the dirty work of overlaying it on the user's screen. by passing a few parameters (imageid ecc) to the applet users will be able to view the image without visible watermarking schemes users won't be allowed to download the image directly users won't be able to download the image somehow by searching the url because all they have is the imageid, not the url (that is processed internally by the applet) users won't be able to copy it from the cache because communication between the server and the applet will be ciphered now the other face users will have to download and install the applet loading a page will need more time and resources (both on client and server side) users without HW overlay support won't be able to view anything (note: overlaying was introduced in voodoo3. i think it's 5 years ago... all the new HW should have it) and the evil one if some cracker gets the applet can (with really hard work) understand the way imageids are converted in the images urls and f**k the entire system. i had this idea while reading this forum in the past 5 minutes. i may have told only stupid things, but maybe not. please do excuse me for my poor english...