DOI: 10.1145/1008213.1008232Pirated movies are available for sale at low prices in many online stores such as eBay and MovieGoods. But a new way of distributing pirated movies based on Peer-to-Peer (P2P) networks, in particular BitTorrent (BT), which can cause even greater financial losses to the movie industry, has surged in popularity. The financial losses to the movie industry due to P2P can be more severe and long-lasting because (1) distributing the digital form of pirated movies is much easier; (2) copyright holders or movie publishers can do very little to prevent distribution over P2P networks, and they usually respond passively; and (3) pirated movies exist even before their official release since the Telesync (TS) version of movies shot in the cinema can be easily produced. For the movie industry to come up with an effective anti-piracy strategy to combat BT networks, it is necessary to understand the sharing activity of pirated movies in BT. This article presents data collected from two representative BT discussion groups to explain the file-sharing patterns of pirated movies over BT networks and to analyze their impact on other movies in the same series. "The Lord of The Rings" was chosen for our study. We were amazed at the speed that this unreleased Hollywood movie became available for download in BT. So our study is intended to generate insights as to when BT users began to show interest in the movie, to think about downloading it, to actually download and play the movie, and finally to leave BT undetected. This article concludes with suggestions on the design of an anti-piracy strategy.