One third of all requests to Internet service providers to remove stolen copyrighted material from their servers could likely be defeated in court, according to a study of some 900 notices by two legal experts.

The survey examined takedown notices served to Google and another large Internet provider under the Digital Millennium Copyright Act (DMCA) Section 512. Two provisions of that section require that hosting providers and search providers remove content and links to content in order to gain exemption from possible copyright lawsuits. The music and movie industry typically use a different provision of the section to ask for suspected infringers to be cut off from the Internet.

According to the study, thirty percent of the notices could be readily challenged in court on clear grounds, such as a substantial fair-use argument and the likelihood that the material is uncopyrightable. One out of 11 notices had such a significant legal flaw - such as not identifying the infringing material - as to render the notice unusable. Moreover, more than half of the notices for link removal that were sent to Google were sent by businesses targeting apparent rivals, the report said.

While the authors of the study admit it uses a small sample set, the conclusions support contentions that the DMCA has been used to hobble expression on the Internet, even among security researchers, who have an explicit exemption in the law. The row with media giant Sony BMG over its controversial copy protection technology had some researchers worried that investigating the protection would place them at hazard from a DMCA lawsuit.

If more Internet service providers published every takedown notice they receive, as Google does, a more statistically valid study could be performed, the authors stated.

Copyright © 2005, SecurityFocus