A new study by Michael Piatek, Yoshi Kohno and Arvind Krishnamurthy at the University of Washington shows that copyright owners’ representatives sometimes send DMCA takedown notices where there is no infringement – and even to printers and other devices that don’t download any music or movies. The authors of the study received more than 400 spurious takedown notices.
Technical details are summarized in the study’s FAQ:
Downloading a file from BitTorrent is a two step process. First, a new user contacts a central coordinator [a "tracker" – Ed] that maintains a list of all other users currently downloading a file and obtains a list of other downloaders. Next, the new user contacts those peers, requesting file data and sharing it with others. Actual downloading and/or sharing of copyrighted material occurs only during the second step, but our experiments show that some monitoring techniques rely only on the reports of the central coordinator to determine whether or not a user is infringing. In these cases whether or not a peer is actually participating is not verified directly. In our paper, we describe techniques that exploit this lack of direct verification, allowing us to frame arbitrary Internet users.
The existence of erroneous takedowns is not news – anybody who has seen the current system operating knows that some notices are just wrong, for example referring to unused IP addresses. Somewhat more interesting is the result that it is pretty easy to “frame” somebody so they get takedown notices despite doing nothing wrong. Given this, it would be a mistake to infer a pattern of infringement based solely on the existence of takedown notices. More evidence should be required before imposing punishment.
Now it’s not entirely crazy to send some kind of soft “warning” to a user based on the kind of evidence described in the Washington paper. Most of the people who received such warnings would probably be infringers, and if it’s nothing more than a warning (“Hey, it looks like you might be infringing. Don’t infringe.”) it could be effective, especially if the recipients know that with a bit more work the copyright owner could gather stronger evidence. Such a system could make sense, as long as everybody understood that warnings were not evidence of infringement.
So are copyright owners overstepping the law when they send takedown notices based on inconclusive evidence? Only a lawyer can say for sure. I’ve read the statute and it’s not clear to me. Readers who have an informed opinion on this question are encouraged to speak up in the comments.
Whether or not copyright owners can send warnings based on inconclusive evidence, the notification letters they actually send imply that there is strong evidence of infringement. Here’s an excerpt from a letter sent to the University of Washington about one of the (non-infringing) study computers:
XXX, Inc. swears under penalty of perjury that YYY Corporation has authorized XXX to act as its non-exclusive agent for copyright infringement notification. XXX’s search of the protocol listed below has detected infringements of YYY’s copyright interests on your IP addresses as detailed in the attached report.
XXX has reasonable good faith belief that use of the material in the manner complained of in the attached report is not authorized by YYY, its agents, or the law. The information provided herein is accurate to the best of our knowledge. Therefore, this letter is an official notification to effect removal of the detected infringement listed in the attached report. The attached documentation specifies the exact location of the infringement.
The statement that the search “has detected infringements … on your IP addresses” is not accurate, and the later reference to “the detected infringement” also misleads. The letter contains details of the purported infringement, which once again give the false impression that the letter’s sender has verified that infringement was actually occurring:
Notice ID: xx-xxxxxxxx
Recent Infringement Timestamp: 5 May 2008 20:54:30 GMT
Infringed Work: Iron Man
Infringing FileName: Iron Man TS Kvcd(A Karmadrome Release)KVCD by DangerDee
Infringing FileSize: 834197878
Infringing URL: http://tmts.org.uk/xbtit/announce.php
Infringers IP Address: xx.xx.xxx.xxx
Infringer’s DNS Name: d-xx-xx-xxx-xxx.dhcp4.washington.edu
Infringer’s User Name:
Initial Infringement Timestamp: 4 May 2008 20:22:51 GMT
The obvious question at this point is why the copyright owners don’t do the extra work to verify that the target of the letter is actually transferring copyrighted content. There are several possibilities. Perhaps BitTorrent clients can recognize and shun the detector computers. Perhaps they don’t want to participate in an act of infringement by sending or receiving copyrighted material (which would be necessary to know that something on the targeted computer is willing to transfer it). Perhaps it simply serves their interests better to send lots of weak accusations, rather than fewer stronger ones. Whatever the reason, until copyright owners change their practices, DMCA notices should not be considered strong evidence of infringement.