60 Minutes ran a scare story about file sharing this week: Pirates Of The Internet
Fortunately, federal law already prohibits piracy and provides for harsh penalties in 18 USC § 1652 Citizens as pirates:
Whoever, being a citizen of the United States, commits any murder or robbery, or any act of hostility against the United States, or against any citizen thereof, on the high seas, under color of any commission from any foreign prince, or state, or on pretense of authority from any person, is a pirate, and shall be imprisoned for life