What apps like this do is create social pressure on people to not copy things. If you use SnapChat it is obvious that you want the communication to be treated

What apps like this do is create social pressure on people to not copy things. If you use SnapChat it is obvious that you want the communication to be treated with more "sensitivity" than a Facebook post. The common complaint that it is impossible to self destruct data is obvious to most people. If it is technically impossible to make something un-shareable then the only thing you have left is social convention.