Content Publishing and Downloading Practice in BitTorrent

BitTorrent has been popular over the last decade. However, few studies have made serious efforts to understand who and why publish torrents, and what strategies are adopted by publishers. In this paper, we study the current content publishing practice in BitTorrent from a socio-economic point of view, by unraveling (1) how files are published by publishers, (2) what strategies are adopted by publishers, and (3) how effective those strategies are. To this end, we conduct comprehensive measurements on one of the largest BitTorrent Portal, The Pirate Bay (TPB). From the datasets of 52 K torrents and 16 M users, we classify the content publishers into three types: (i) fake publishers, (ii) profit-driven publishers, and (iii) altruistic publishers. We show that a significant amount of traffic (61%) of BitTorrent has been generated (i.e., unnecessarily wasted) to download fake torrents. Therefore, we suggest a method to filter out fake publishers on TPB by considering their distinct publishing patterns learned from our measurement study, and show the proposed method can reduce around 45% of the total download traffic. We also reveal that profit-driven publishers adopt different publishing strategies according to their revenue models (e.g., advertising private tracker sites to attract potential new members, or exposing image URLs to make people click the URL links).