• by Wendy Davis  @wendyndavis, June 2, 2010

A California Facebook user has sued the social networking company for allegedly sharing his personal information with advertisers.

In a complaint filed late last week in federal district court in San Jose, David Gould of South Lake Tahoe alleges that Facebook violated its own privacy policy by disclosing to advertisers a host of information about users who click on ads, including their real names, current cities, schools attended and friend lists. Gould is seeking class-action status.

"Facebook advertisers are able to gain the ultimate demographic information," the lawsuit alleges.

Gould alleges in his complaint that Facebook sends "referrer headers" to advertisers whenever people click on ads. Once marketers have those headers, advertisers "can simply navigate back to the specific user's profile and obtain any personal information the user has made publicly available," Gould alleges in his lawsuit. "And remember," he adds, "the default privacy settings that many users never change make the user's name, photo and more available."

Gould alleges that Facebook is breaching its contract with users by sharing their data, because the company states in its privacy policy that it doesn't disclose users' information to advertisers without people's consent.

Facebook spokesperson Andrew Noyes said in a statement that the company believes the lawsuit is without merit and intends to fight it vigorously.

The allegation that Facebook was sending data about users to marketers via referrer headers first surfaced last summer, when two computer scientists from AT&T and Worcester Polytechnic Institute published the report, "On the Leakage of Personally Identifiable Information Via Online Social Networks."

The researchers concluded that many social networking sites "leak" personally identifiable information by including it in the HTTP header information that is automatically sent to ad networks.

At the time, a Facebook spokesperson said that referring URLs only provided information about the profile page a user had been on when he or she clicked on the ad, but didn't reveal whether that user was the person featured in the profile or a friend of the member. But Harvard professor Ben Edelman said last month that Facebook automatically embeds a profile tag in referring URLs when users view their own profile pages.

Late last month, Facebook said it revised its code and no longer sends marketers information that could be used to identify which member clicked on an ad.

Gould is being represented by Michael Aschenbrener of EdelsonMcGuire. Aschenbrener has been involved in several other high-profile lawsuits against Web companies including a lawsuit against eBay for allegedly discriminating against deaf sellers by requiring them to use a telephone to verify identity.