Mate thats horrible. In the world of art, as in the world of fashion, its very hard to prove copyright, intellectual or otherwise, but you should have enough to work with there as they are blatant and obvious rip offs! It really sucks that you do all the hard work and someone else profits big time from your work. But any law firm will be able to see that. Its just that it would be a shitfight of a case. I hope someone helps you out though. Good luck, and by the way your sandman tshirts look great. Im gunna order one!