Before the advent of services such as Spotify and Netflix, users in Western countries had not so many opportunities to legally listen to online music. At that time, many downloaded pirated copies of music and video from file sharing. In early 2004, only in the US about 8 million people used P2P applications, such as LimeWire, eDonkey, Kazaa and BitTorrent. It's no surprise that the applications were interested in the US National Security Agency.

As reported by The Intercept, referring to documents provided by Edward Snowden, the special service established a special group to study P2P. According to the internal dispatch of the NSD SIDtoday for 2005, the special services were not interested in protecting copyright or combating piracy. The special group was to find out whether it is possible to obtain valuable intelligence data by monitoring P2P traffic.

To track P2P networks, the NSA had to decode the protocols used by various services, and in some cases also crack the encryption in order to see the transmitted files. "We have developed a method that allows us to decrypt and decode Kazaa and eDonkey traffic in order to determine which files are being forwarded and which requests are being performed," one of the special group members informs in the newsletter.

NSA managed to use Kazaa to retrieve data from registry entries on the computer, including e-mail addresses, country codes, user names, downloaded file locations, and encrypted lists of recent requests. At present Kazaa service is no longer used, and its site was closed in 2012.

The eDonkey network is still active, although it is no longer as popular as before. Service still uses the same vulnerable protocol as in 2004. The popular eMule client to connect to the eDonkey network has not been updated for more than seven years. As the developers of the program told reporters, The Intercept, security was never their goal. According to them, encryption of the protocol is rather obfuscation rather than encryption itself. "NSA certainly could spy on traffic if it wanted to.

The prevention of this was not the purpose of encrypting the protocol, "the developers noted..

P2P or peer-to-peer - peer, decentralized or peer-to-peer network. It is an overlay computer network based on the equality of participants. Often in such a network there are no dedicated servers, and each node is both a client and serves as a server. Unlike the client-server architecture, such an organization allows you to keep the network working at any number and any combination of available nodes.