Can Terms of Use Stop Richard Prince?

According to this article, the photographer, Richard Prince, is ripping off using other people’s Instagram photos – and selling them for lots of money ($90,000)!  Arguably, he can do this because it’s fair use  — he blows the images up and makes minor changes to them, like removing captions and adding comments.  (One could also argue that it’s not fair use because he doesn’t change them enough).  Putting aside the copyright related issue (fair use or not fair use) and the privacy issue (are there any privacy related claims when you post on Instagram for the world to see – but don’t mean to have your photos used in this way?) – what intrigues me are the contract related issues.  I took a quick peek at Instagram’s latest terms of use and there’s nothing in there that would really help someone whose photos were being used by Richard Prince.   And while Instagram’s Community Guidelines are thoughtful and cover a variety of topics, they don’t address this problem.  But could its TOU address this issue – and should it?  What if Instagram put in its Terms of Use a provision that forbade visitors to its site from using other people’s photographs for any purpose?  If so, what could the company do if a user violated that term?  It could, of course, ban the offending user from Instagram.  Could it sue for breach of contract – and if so, what damages could it claim? If people started to copy users’ photographs from Instagram and use them for their own purposes that would likely hurt Instagram’s business.  Instagram should consider how its Terms of Use can be amended to protect their users from this type of unauthorized use.