On Mac computers, using the "Command + Shift + 3" command will take a "screen shot" of the current screen. I've seen some software that will create an "inverse" effect of the current on-screen image when "Command+Shift" are held down, therefore adding an extra layer of image protection.
I don't know how difficult it would be in a programming standpoint, but is there a way to create an option to enable/disable "Command+Shift" protection?
I know I might be vague here, so let me know if you'd like me to elaborate.
Thanks!