I don't know if you're aware or not, but there is a group using this image as promotion for their schooling and classes. I don't know if you're associated with them, but their name is "The Art Department"( [link] . If not, you might want to make them aware that you know they are using your stuff.I hope this isn't antagonistic if they have legitimate rights to use it, or if you are affiliated with them, but I wouldn't want them to get away with it either if you didn't give them the permission to use it.