got a proper lol out of me.
Likewise.
To
mim - As previous replies in this thread have already said - ignore it. However, take the image concerned down from where it resides. That won't make any difference to anyones ability to see said image was previously on your website ( they can simply use Wayback to see old archived versions of sites ) but it will show you have complied with any "cease and desist" requests.
This cropped up with me a good few years back and after a long period of research into it all it transpires that Getty simply punt these letters out in the hope that some folk pay up. Many don't. The thing is, Getty will "sell" your copyright infringement "debt" to a collection agency and they will attempt to recover the money from you. Their concern and business interests lie with getting the people who are frightened by the initial demand to pay up. Ignore the letter and they won't give two hoots because it's likely that the next person or the person after them will pay up.
In addition, or at least at the time this happened to me, upon looking at it all from a legal enforcement point of view, Getty - a US company had passed on their "debt" collection to an agency based in Southern Ireland who then instructed another party based in England to attempt to recover the "fee" from me, based in Scotland. So 3 different legal systems working away there, all at odds with each other in varying degrees.
So in short, take the offending image down, ignore the threatening letters and don't be concerned with it.
One positive thing came out from it all from me, it was a lesson learned in my early days of web design. I mistakenly and foolishly used a copyrighted image. I wasn't aware it was copyrighted at the time. However since then I'm very, very careful about what images I use on sites.