Even the foremost thinker in security, Dan Geer (http://en.wikipedia.org/wiki/Dan_Geer), once said: "...The most serious attackers will probably get in no matter what you do. At this point, the design principal, if you’re a security person working inside a firm, is not no failures, but no silent failures."

In the same respect, you can't really stop people from taking screenshots or take a photo of... a photo. What we do is we put a watermark of the recipient in the image. This way, if that image get released anywhere, you knew who was the culprit and you can take further actions.

No box is ever impenetrable, then the next best thing is to know when, what, why, whom of the penetration. I hope that helps. It is a difficult problem to solve, however, we have to do something!

Thank you for your thoughts.

-V.