Privacy Study: Top U.S. Web Sites Share Visitor Personal Data
A study released Tuesday shows that 45 percent of the top 185 U.S. Web sites transmit identifying details about their visitors to at least four outside Web sites.
The data transmitted was primarily a “username” — which is the name a person uses to log into a Web site — or a user ID assigned by the Web site to a user. It was usually transmitted through referrers — which is information about the Web page transmitted automatically.