NeoNemesis - regardless of what Kazaa does/is, you should still watch talking about ripping them off
And SlowBit, welcome to the Internet. No, you can never be TOTALLY sure you aren't getting spiffed (unless you cut yerself off from the web completely). I've done a lot of work in some very secure places, and with all the firewalls and protocols, they still get the occasional bit of spam/spyware/malware/etc. There's a point when you gotta look at what's practical (as far as your enjoyment level and reality) and what is bordering paranoia.