Pinterest, we have a problem.
Adam Rifkin stashed this in User Generated Content
If you snap an awesome photograph, upload it to your blog, and someone pins it, that person is either (1) claiming exclusive ownership of it; or (2) giving Pinterest your consent to reproduce it (and you just thought you were being flattered).
If some photographer sues you for violating their copyright, Pinterest washes its hands of any and all legal liability.
Does pinning an image to Pinterest fall under the provisions of Fair Use? The answer is unclear.
Here's an interesting post from the American University Law School blog:
However, the key provision that is making some people nervous about Pinterest is that its license is irrevocable and perpetual, meaning that even if you delete content, Pinterest can theoretically still use the content however they wish.
Slippery slope of a new area creates all kinds of opportunity for terraforming. Good news is that Pinterest seems to be taking this area seriously -- that's actually good for the whole ecology. Their new general counsel is very well respected. http://www.webpronews.com/pinterest-hires-former-google-lawyer-michael-yang-2012-06
They are on the leading edge of "fair use" -- I'm very interested to see what they come up with as best practices.