Security Space, a Web site run by eSoft, Inc., released the results of a recent survey that reveals the top 100 domains that are using Web bugs. Web bugs can track the Web surfing habits of users when they visit a Web site by following the trail as the users visit other Web sites.
Web bugs can take the form of a tiny 1-pixel by 1-pixel image embedded into a Web page, where the bug is essentially invisible to the human eye. Alternatively, bugs can be URLs that use a script to direct the user through a tracking agency site and then redirect the user to the actual content—all without the user's knowledge.
In August 2000, the Privacy Foundation released a report detailing how someone could even embed HTML containing Web bugs into Microsoft Word, Excel, and PowerPoint documents. The Security Space survey results reveal at least 10 different Web-bugging methods that the sampled sites are using.
According to the survey results, Security Space sampled 701,176 pages from 101,991 different sites and correlated the data to reveal the top 100 domains that track Web bugs. The top three Web-bug trackers are doubleclick.net, akamai.net, and linkexchange.com (owned by Microsoft). Other top 100 notables include Excite, HitBox, ListBot, Network Solutions, and surprisingly, security software maker WebTrends, with its WebTrendsLive Web site.
Many users aren't aware that someone is tracking their Web activity. The Privacy Foundation maintains a Web site with a bug FAQ to help users understand Web bugs, including information on how they work.