Aren't there bittorrent clients which autodetect and autoblock clients which connect, but neither upload nor download? Doh! Link to a somewhat more informative, less beeby, story: http://www.newscientist.com/blogs/onepercent/2012/09/honeytr... And the lead researcher http://www.cs.bham.ac.uk/~tpc/home.html Published paper link snaked below! :)

(A previous paper: Analysis of BitTorrent Peers' Behavior and Monitoring Trends http://www.kaspersky.com/images/camilo_andr%D1%83s_gonzalez_... which was based on the Snark Project, updated)