you will most likely receive additional letters, especially since you responded to them already, they now think they have a fish on the hook. By you telling them you are being advised by your lawyer is not sufficient, kinda the same as them telling you they own the image. Now if your lawyer sends them a response, that would be different, as then you would be represented by council, and they would have to send everything through him/her. I'll reiterate again, it's not in their interest to file suit, it would cost them more then it's worth, they know this or they would be filing suit daily.
I'm not "rejecting" anything I'm simply disagreeing, I don't see how "commentors" can make it fair use..they did not post it, using it to "illustrate a topic" ( your words) is not fair use... Using Public domainis fine on this forum, but public domain images do not fall under copyright and that term is often misused as is Royaly Free..
http://fairuse.stanford.edu/overview/public-domain/welcome/
https://en.wikipedia.org/wiki/Royalty-free
I'm not "rejecting" anything I'm simply disagreeing, I don't see how "commentors" can make it fair use..they did not post it, using it to "illustrate a topic" ( your words) is not fair use... Using Public domainis fine on this forum, but public domain images do not fall under copyright and that term is often misused as is Royaly Free..
http://fairuse.stanford.edu/overview/public-domain/welcome/
https://en.wikipedia.org/wiki/Royalty-free