LIVE from Threat Center: Resources : Intrusion Prevention Datasheet Network ThreatPak P2P Presentation

Enforcing Instant Messaging and Peer-to-Peer policies is difficult for today's IT manager, yet those areas still represent significant security vulnerabilities present in the network. IM and P2P are new source criminals trying to infect computers through Virus, Spyware and Phishing attacks.  Not only that, they are an increasing source for confidential information leaving the network undetected.  These applications also represent a substantial drain on employee productivity, as most managers are now clearly aware.  
 
IT managers should be enforce IM applications such as AIM, ICQ, Goggle Talk, MSN Messenger and AOL Instant Messenger, as well as and peer-to-peer applications such as KaZaa, Limewire, BitTorrent and eMule/Donkey.  Most of the IM and P2P applications are designed to evade firewalls, often disguising their traffic as web surfing or other traffic that is allowed through the firewall.  To monitor and block usage requires Deep Packet Inspection (DPI) that can determine the application that is generating the traffic, not just the ports it uses to communicate with outside sources.  In a similar fashion, IT managers should monitor and enforce the use of social networking sites such as MySpace and Friendster.

IM/P2P/Social Networking Security Checklist: