I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
There are some photographs that are under common creative license but the author is up front: photographs are either in public domain or under CCL. That is, those that he didn't take. He explains this in the beginning of the book, as well as saying that he acknowledged them at the back as requested by the photographs under the CCL.
This isn't a guarantee, but I've found that people who are guilty won't acknowledge this as clearly, so I'm tempted to trust him. My computer isn't letting me reach the links, either from this book or the previous one, so all I have is what the authors give me and my gut instinct.
This seems more honest to me. And I enjoyed the photographs as well, although there was varying quality as far as composition went, so three stars.