IT's called SPYWARE.......and if RIAA wanted to supeona stuff from Kazaa, more than likely, Kazaa will give in. They don't want to be sued for "impeding" the legal process. I'm sure in the legal agreement there is some clause where it states that Kazaa is not responsible for what their users use the software for and will cooperate with authorities if need be.
that's how they are getting most people, is through the internet PROVIDERS. RIAA gets the IP off Kazaa, then goes straight to the internet providers to get your info. But i'm sure you all know about this alreadyl