According to an advisory from internet privacy activist Richard Smith, Windows Media Player 8, which comes with Microsoft's Windows XP, contacts a Microsoft Web server each time a new DVD is played on a computer.
The server is given a unique fingerprint for the DVD and the media player client, allowing Microsoft to track what movies are watched on a particular PC, Smith wrote in his advisory posted at www.computerbytesman.com/privacy/wmp8dvd.htm .
The unique code identifies the software, not the person using it. However, Smith claims that this anonymity could be lifted if the user signs up for the Windows Media e-mail newsletter. The locally stored file could pose a privacy problem if the PC is used by more than one person. A user could uncover what movies another user is watching.
Users can turn off the Web lookup feature in Windows Media Player 8 by choosing to work offline in the "File" menu, Microsoft said. Another option is to change the privacy settings to block all cookies.