“Millions of people have flocked to Pinterest to create virtual scrapbooks of images they pin to their website. But the ease at which users post photos from the Web is drawing copyright concerns.”
For ideas on how to avoid copyright infringement on Pinterest, see my previous scoop: How Brands Can Use Pinterest Without Breaking the Law http://bit.ly/wvqFSm
The core issue is whether publicly available images can be repurposed without attribution or permission. Not exactly the same issue as with Napster . . .