Is PI-nterest getting IP back-to-front?

You may have come across articles like this one that highlight the potential copyright infringment of Pinterest

If a Pinner pins an image from a photographer’s site without their permission, is that copyright infringement or “fair use”?

If a photographer can prove damages from loss of work due to “dilution of value” resulting from being pinned and repinned thousands or times, do they have a right to legal recourse? If so, who is liable — Pinterest or the Pinner? Try searching for images in Google and notice how many times you see Pinterest in the search listing — is this competing with the original artists work, or is it benefiting the artist? Many artists are happy to allow selected websites and bloggers to embed their work in exchange for attribution, but when a Pinterest user comes to that site or blog and pins the image, there is no attribution back to the original artist — the blogger is wrongly credited instead. Is this “fair” for the original artist?

What do you think?