I recieved a lettler from Dunlap, Grubb Weaver ask to sent them $2,900 they said I download a movie Cornered?

They are from Virginia I live in Ca, they said they have the IP address, the Isp information date n time, they said it was share n utorrent de file name something like BTiH and the GUID assign to my IP address, What is it all about it? I ask my internet provider about those persons,they don't know nothing about it. Dunlap, Grubb n Weaver said there are 2,177 persons in the suit, and that the BitTorrent protocol P2P makes even small computers with low bandwith capable of participating in large data transfers across a P2P network, I don't know nothing about computers, only the basics I don't know what are they talking about, even less about the movie call "Cornered", somebody suggest call the attorney district but What I need to tell them? how can i find more persons in my same situation please help!!!