This reminds me of my friend's product http://www.scribblepics.com/ (but they do it through mainly big tourism type partnerships rather than directly b2c).
Pinterest user's pin with the "promise" that they own the content. Well we know that's not happening. But what happens when PinPigeon prints images with copyrighted content from Coke, Budweiser, Apple, etc? Or, less identifiable but equally protected?
The DMCA works wonderfully to protect online services from "user uploaded" content, but I'm not aware of a means to enjoy similar protection in the physical world. There must be some measure if liability, because, just an example, instant photo places frequently refuse to print things like wedding photos without a copyright release. The photos don't even have to be marked with a copyright. Just the fact that most wedding photos are taken by a professional is enough for them to require a release. I can't imagine they do this just to be annoying.
