Reading the Pinterest terms, I'm not sure if I can use Pinterest photos. Assume I've done due diligence and verified that the photographer is really the copyright owner of the photos, since the photos are on Pinterest, can I use them without permissions? From pinterest: "You grant Pinterest and our users a non-exclusive, royalty-free, transferable, sublicensable, worldwide license to use, store, display, reproduce, save, modify, create derivative works, perform, and distribute your User Content on Pinterest solely for the purposes of operating, developing, providing, and using the Pinterest Products."
Everything sounds awesome - like a Creative Commons license almost - until this part " ... solely for the purposes of operating ... and using the Pinterest Products."