Users who have downloaded copyrighted music, video and other content through a BitTorrent client within the last three years have likely had their IP address logged by monitoring companies, according to research by Tom Chothia and colleagues at the University of Birmingham, United Kingdom. They will present their conclusions this week at the SecureComm conference in Italy. Monitoring of popular BitTorrent files is so prevalent, in fact, that the researchers concluded that most users will have their IP addresses logged by copyright-enforcement authorities within three hours of download. Chothia and team set up a fake pirate server online to perform their research for more than the past two years. They were able to measure "the activity of 1,033 swarms across 421 trackers for 36 days over 2 years," and over 150 GB of BitTorrent traffic data, according to the full paper (PDF file). The researchers were able to identify monitoring companies by comparing the download progression of users on the BitTorrent files. While a "regular" peer user's client will download the BitTorrent data in a steady progression toward completion, a monitoring peer downloaded data randomly over time, to give the illusion of activity to cover the companies' true intent. Additionally, they found that using blocklists was not an effective practice for preventing being watched and logged by the monitoring companies. While the researchers were able to match some IP addresses of suspected monitoring companies with those on some blocklists, they found both false positives and false negatives on the lists.