When you bookmark a page, the browser requests the favicon.ico file. The web surfer is unaware that a request has been made and users can not turn this feature off. The web site can then use their logs to build a record of the user's bookmarked pages. Visitors could then be tracked by a cookie. This would allow sites to build more profiles of visitors interests. I'm not sure how you could do this, so if anyone can fill me in on the details please contact me. Most people do not think the privacy concerns that result from this bookmarking/favicons scheme are anything to worry about. (No one has created a real uproar regarding the privacy issues related to favicon branded bookmarks).