In a folow up to our What Banner Ads are saying about us story, CNN has this in depth story on one company, IDcide, that has developed a cure for this by providing a browser plug-in that discriminates between first-party (coming from the site you\'re visiting) and third-party (coming from other servers) cookies. The tool, called the Privacy Companion, can provide varying levels of security -- either blocking no cookies, just third-party cookies, or all cookies.For example, the New York Times on the Web requires a free login before entering. If you have cookies disabled, you won\'t be automatically let back in when you return to the site. But a tool like Privacy Companion can allow the first-party cookie from the Times to let you into the site, but disallow third-party cookies from ad companies that track your habits while you\'re there. As the tracking networks work through the banner ads, those ads appear broken with the security in place.
If the networks are allowed to track, they can record all sorts of information about your habits. Security consultant and privacy watchdog Richard M. Smith showed how DoubleClick can mine personal data from a user\'s habits on such popular Web sites as AltaVista, Travelocity, DrKoop.com, Buy.com and the Internet Movie Database. By visiting less than 10 sites, the network had his name, street address, e-mail address and birthday. The ad company also saved transactional information such as the route of a plane trip, what search terms he used in a search engine, and what products he browsed on e-commerce sites.