Lately the AO community have seen some question like 'is kaaza safe' and all sort of questions regarding the p2p softwares. Today i came across this paper...and i hope it will be able to answer most of the questions regarding the security threats and the P2P softwares.
source here : http://vulns.com/article.pl?sid=03/08/19/2057227szyzyg explores P2P threats in this feature: "Napster wasn't the first peer to peer system, it was merely the first to bring Peer to Peer (P2P) file sharing to a wide audience and make it accessible to everyone. P2P networks are generally used to share files between users collaborating in the network, and for users they make a lot of sense: searching is easy and sharing is even easier. It's this combination of powerful content acquisition and ease of use which makes these applications popular with users and a major issue for network administrators. So what kinds of threats do P2P users bring?"