First, I'd like you to read this post.
Due to this, my phobia of something like that happening to me or anyone else I am close to has gone right back up. Im going to be slapping watermarks on my pieces (once again) in addition to my signature on the images. The last thing I want is some retail store stealing my designs without my permission and making a profit off of it. I'd advise everyone take measures to protect your art as well because art theft is real. Its something we can't escape no matter what. And the better your art is, the higher quality it is, the more likely its going to be snatched right from under your nose. I've seen it happen time and time again on this site and of course, DeviantArt will do nothing about it, as they always have.
Protect your art! Watermark it, sign it!