See http://www.torproject.org/eff/tor-dmca-response.html.en , and
http://www.torproject.org/eff/tor-legal-faq.html.en#DMCA . You should
contact the EFF if you need legal help. Note also that your ISP might
have terms against "running servers" in your TOS, and so you might end
up getting told to shut down your Tor node or getting disconnected.