for including DRM software with a music CD that runs even when the CD is not being played, and . The software is difficult to remove and, if removed manually, could shut off access to the computer's CD player.
It has been rumored that other recording giants including EMI and the Universal Music Group use technology similar to that used by Sony; an EMI spokesman said on Friday that the DRM used on EMI's CDs can be completely removed if the user doesn't want to play the CD any more.
"Thethat we're using can be easily uninstalled with a standard uninstaller that comes on the disc. EMI is not using any software that hides traces of the program. There is no 'rootkit' behavior, and there are no processes left running in the background," said an EMI spokesman in a statement.
EMI also said it was not working with First 4 Internet, the U.K. company that created the copy-restriction software for Sony, although it is trialing other content-protection software.
"EMI is not using First 4 Internet technology. We recently completed a trial of three content-protection technologies (Macrovision's CDS300, SunnComm's MediaMax and SonyDADC's key2audioXS), and First 4 Internet's technology was not one of those tested," said the spokesman.
Universal Music Group was unable to provide comment in time for this article.
Although Sony's use of rootkits has sparked an outcry, users would find it difficult to sue Sony in the U.K., even if their computer was damaged by its copy-restriction software, according to legal experts.
Ingrid Marson of ZDNet UK reported from London.