The researchers were able to show that indirect detection is still widely used. By using 13 different machines on the University of Washington campus, the researchers were able to "advertise our presence as a potential replica without uploading or downloading any file data whatsoever." Despite having no infringing content on their machines, the takedown notices poured in, meaning that "direct detection" could not have been used in these cases.
The researchers used some of these trackers to "frame" one wireless access point, three networked (and IP-accessible) printers, and a desktop PC that was not currently using BitTorrent at all. Each of the machines received DMCA takedown requests. An attempt to "frame" IP addresses with no machine attached failed to attract any complaints, however.