The question has come up on [[Wikipedia:Possibly unfree images]] about
images licensed under the UN license. That license says:
"UN photographs can be reproduced for editorial purposes only. They may not
be used in advertising. All photos used must show the UN Photo credit line."
Personally I think these images are "free enough", as they could be used by
any encyclopedia, commercial or non-commercial. But a couple people have
argued against this.
I'd like to invite anyone interested to comment at
http://en.wikipedia.org/wiki/Wikipedia_talk:Possibly_unfree_images