dA cannot do anything against it, mainly because it's off site. deviantART doesn't own your submissions so the copyright is still yours, so it's up to you to take legal action if your copyrights were infringed. Please see our Need Help? thread when you need help with dA
I believe there was already thread about this place. I figure it's like one of those places that just regurgitates links and references to hundreds of other places. I've seen that a lot with my music, same goes for the art. I don't think much of it because thousands of deviants can be found there.
Darn it, I have "My Fair Lady" songs stuck in my head. It seems these people have no real life, and sit there using our images on their site. They look like a bunch of fools, to me. Though they have given credit... I'm too bloody lazy to ask for a linkback. I don't think they are passing it off as their own work. (That would piss me off.)