Speak for yourself, Dominic. I do my best on the rare occasions I use another's work to give credit, get permission, or at least conform to fair use conventions. But I never intentionally "steal" imagery, and If I found that I had done so, by neglect or error, would immediately take down any such image. I don't use pinterest at all, for example, because when you pin an image, you are claiming to own the rights, per the user agreement of the site.