P2P networks are key enablers of the Internet grey market by acting as distribution mechanism of choice for pirated movies, music or applications. They are also a significant enabler of malware as both an infection vector and a command-and-control (C2) channel. Palo Alto Networks Application Usage and Risk Report issued today shows that the use of peer-to-peer (P2P) technologies in the enterprise is surging. BitTorrent alone accounted for 58 times more bandwidth than Dropbox, RapidShare, Box.net and other 68 variants combined.
Source: https://threatpost.com/hidden-security-risks-p2p-traffic-062712/76739/