graeme_p - 12:35 pm on Aug 6, 2013 (gmt 0)
Got a lawyer. I suspect the lawyer will tell you to register your copyrights, and will send out another round of DMCA notices, and if that fails sue.
Remember, you can get damages, so you can cash by suing, not just remove the material.
Why even have a copyright?
Because it is very useful for people who can afford expensive lawyers and enforcement systems. They do rather well out of it. The rest of us get a few fortuitous crumbs.