An anonymous reader writes, "In the U.S. Congressional Inquiry into the HP spy scandal, it was revealed that HP used Web bugs to track the source of leaks. HP's Fred Adler considers them a useful investigative tool which HP will keep using. Since dubbed PattyMail after HP Chairwoman Patricia Dunn, Web bugs have been around for a while. But it turns out the vulnerability they represent is far worse than first thought. Microsoft Outlook won't have a patch until 2007. The company at the center of the scandal claims they've done nothing wrong. But could repressive governments use them to track down critics? Can anything be done to stop Web bugs?"