A friend of mine has self-published a graphic novel and posters, claiming all the photographs, paintings and graphic design inside of it is his own.

I was suspicious - none of the art has a consistent style - and the work I have personally seen him do is comic style illustration, never in the mediums and styles in the book. He's also claiming to have done all the work in six months, which I think would be nearly impossible.

I Google image searched one of the landscapes in his book - very simple, typed in, say, "autumn forest" - and there it was, a stock image on the third search result page. He'd just put a filter on it.

I'm worried that he has not used just stock images, but that he's stolen other artists' work. He's making good money off the book and poster sales, and he's getting accolades for his talent.

It's too difficult to do an exhaustive image search for all of his stuff, particularly when it appears he has added multiple images to one page, and searching for, like, "smiling lady" would return huge amounts of results.

Any ideas on what can be done? I'd like to make sure I'm right. The landscape search result really worried me. I really hope this guy isn't profiting off others' work.