A few years back my logs showed a popular seller on eBay was hotlinking to one of the JPEG images on my website for their avatar. I noticed it because the user was very active on eBay forums so I was seeing thousands of hits a day - the user would have five forum posts on one page, so five avatars, times a few hundred page views a day, for each forum page. You get the idea.
I remember wondering why eBay allowed an external image instead of uploading an avatar. Hotlinking was a big deal to me as my website was getting popular and hotlinking was stealing plenty of bandwidth and screwing up my stats before I put in protections. I repeatedly messaged the user, sent maybe a dozen complaints to eBay - all were ignored.
Finally after a week of this guy stealing my bandwidth I decided to replace the image they were linking to with an image of the male anatomy. This was the user's avatar for about a day before I saw their account was suspended. I'm wondering if this might be a similar situation & the avatar was Webmaster's Revenge?