A Pirated Gold Show Needs to be Taken Down

[porn]

I need help. A site called LiveViolet stole one of my Gold Show videos and uploaded it to their site. I've written them 3 times to take it down, but they are ignoring me. What is the next step to take?

This is the first time it's happened to me. Is there some kind of formal letter I write? Something involving DMCA violation or a cease and desist?