Well, I've been quite the detective today. I noticed, when having a periodic check of my site statistics, that my biggest referrer (by a long way) was a Navy Wives bulletin board - somewhat of a surprise, to say the least. I couldn't see any obvious links to my site on this page, but after a bit of digging in my recent visitors log, I found out what was happening.
Someone signing herself as 'Susie' had used one of the images in wings open wide in her signature on the board. Now, don't get me wrong -- I'm flattered that anyone likes the image enough to bother to use it -- but there are two things about this whole business that have really hacked me off. First, all of the works in wings open wide are covered by a Creative Commons Licence which clearly states that people are welcome to copy, distribute or display the work, but only if they give the original author credit, which Susie certainly didn't do. Since the Creative Commons Licence is very generous in what it allows a licensee to do, I think it's downright rude to violate it, not to mention illegal. Second, Susie didn't even copy the image to a local drive (which is why all the referrals were showing up). So, not only did she use it without attribution, but she's also stealing my bandwidth.
Unfortunately, Susie doesn't list her email address on the board, nor could I email the administrators of the board without registering on it. So as a temporary measure, I've changed the URL of the image — so that her sig will break — and put a message to Susie on wings open wide in the hope that she might visit to find out what's going on. Grrrr.