Characterizing dissemination of illegal copies of content through monitoring of BitTorrent networks

BitTorrent networks are nowadays the most employed method of Peer-to-Peer (P2P) file sharing in the Internet. Recent monitoring reports reveal that content copies being shared are mostly illegal and movies are the most popular media type. Research efforts carried out to understand the dynamics of content production and sharing in BT networks have been unable to provide precise information regarding the dissemination of illegal copies. In this paper we perform an extensive experimental study in order to characterize the behavior of producers, publishers and providers of copyright-infringing files. The study is based on four months of traces obtained by monitoring swarms sharing movies via one of the most popular BT public communities. Traces were obtained with an extension of a BitTorrent "universe" observation architecture, which allowed the collection of a database with information about more than 40,000 torrents, 900 trackers and 1.3 million IPs. Our analysis not only shows that a small group of active users is responsible for the majority of disseminated illegal copies, as well as unravels existing relationships among these actors.