Here is more on the tension (and, in fact, bare knuckle brawling) over the copyright implications of Pinterest.
I very much like the idea of social curation and believe it can be good for content owners, if properly leveraged. That having been said, much (but not all) of the social-curation use of other people’s content is straight-up copyright infringement.
Social curation sites like Pinterest need to find a way to make peace with content rights-holders. Rights-holders need to work with innovative companies to make new media plays a win-win, rather than fighting rear-guard actions to preserve business models.
In short, both sides need to give or both will ultimately lose.