The ISPs are just relaying the information garnered from the outfits that work for the MPAA/RIAA to you. They don't track the torrents or anything. They keep track of the six strikes, re-educate you, and say bad boy/girl. Also to fight back, you have to pay $30 or something like that. Its all pretty shitty.
Anyway the music and movie industry people are using this as a foot hold on the ISPs. I guarantee you that once they get this thing going, a few years down the road they are going to enact even more draconian measures. See litigation is too expensive so why do that when you can go straight to the punishment.