• by Gavin O'Malley , Staff Writer @mp_gavin, October 12, 2011

A Stanford University grad student is sounding the alarm on Web privacy -- or lack thereof. Many Web sites, a new study of warns, send users’ personal information to third parties after they sign up for newsletters, change settings, or take other ostensibly harmless actions.  

"Your Web browsing, past, present, and future, is now associated with your identity," Stanford University grad student Jonathan Mayer writes in his report. All told, the study shows that 45% 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,” AllThingsD notes, citing the study. “It was usually transmitted through referrers -- which is information about the Web page transmitted automatically.”

“Such data leakage may involve a person's name, user name or email address and is pervasive, though not necessarily intentional, among the most popular websites,” the Los Angeles Times writes.

The findings “serve to buttress what privacy advocates have long warned of: Your online travel … is not always anonymous,” writes The New York Times. “It can often be traced right back to rather precise parts of you, including your name and e-mail address.”

“Google, Facebook, comScore and Quantcast were among the top recipients of username and user ID information,” Reuters points out, citing the study. “Federal Trade Commission Chairman Jon Leibowitz said the study would help in the agency's efforts to protect consumers' online privacy and keep at bay what he called the ‘cyberazzi,’ likening behavioral advertising and data collection to the paparazzi known for tracking celebrities' every move.”

According to PCMag.com, “Leibowitz acknowledged that much of the data transferred to third parties is used for targeted advertising, which he said can be ‘beneficial, or at worst innocuous.’”

But "it could be traded throughout an invisible lattice of companies, snowballing into an exhaustive profile of you available to those making critical decisions about your career, finances, health, and reputation," Leibowitz stressed.