I haven't got a clue as to what the FG accosiations are, but here's what I usually do when I find some interesting photos without an obvious source, that I want to share with others:
First, I state on my home page that the pic source is unknown, and second, I usually write that if you're the copyright holder, please notify me if you want me to either remove the pics because you don't want your pics to be online without your permission, or if you want to be credited for the photos. I'll be happy to do so, please lemme know. Or: That's the gist of it.