This is good and bad. Peer 2 Peer file sharing has many legitimate used and is used legitimately in many circumstances. But, I don;t know the specifics of the case. was Limewire deliberately encouraging people to download copyrighted materials ? Effectively this could spell the death of numerous legitimate means of sharing legitimate software. In any event , the RIAA has the bucks so they'll prevail in court.
From my own experiences most of these file sharing services are merely shams for porn, warez, and other illegal crap. Bust them all and shut em down i say. On the other hand I say, let em live. can't make up my mind here.