For the second time in less than six months, two influential U.S. Congressmen have sent a letter to Facebook CEO Mark Zuckerberg questioning the social network's data-sharing practices.
The latest letter from U.S. Reps. Edward Markey (D-Mass) and Joe Barton (R-Texas) was prompted by Facebook's plan to make the addresses and mobile phone numbers of its users available to third-parties.
The feature, unveiled in January, aims to let external application developers and publishers access the full physical address and mobile phone numbers of Facebook users -- although only with their permission.
Facebook withdrew the feature a few days later amid privacy concerns. The company said it plans to relaunch it in a few weeks after some updates.
In their letter dated Feb 2, Markey and Barton, co-chairmen of the House Bipartisan Privacy Caucus, asked Zuckerberg's nearly a dozen questions related to the proposed roll-out.
For instance, the pair ask Zuckerberg whether the updated feature will open more information to third-parties.
It also sought information on measures that Facebook plans to protect personal information of children and teenagers from being accessed by third-parties.
Markey, an author of the Children's Online Privacy Protection Act (COPPA), is working on a bill that would prevent advertisers from tracking the online browsing habits of kids.
The letter also seeks information the opt-in and opt-out options for the new Facebook feature, and on how prominent they will be.
The letter also pointedly notes that Facebook announced the feature in a blog post aimed at developers, and asks how the company plans to formally notify users of the new feature.
The Congressman also ask Zuckerberg to provide details on what information Facebook collected about users before it suspended the feature.
The first letter Markey and Barton sent to Zuckerberg last October sought information on reports that popular Facebook applications such as FarmVille and Texas HoldEm Poker had been collecting and sharing user information with dozens of advertising firms.
Noting Zuckerberg's response to that letter, the Congressman asked: "Why is Facebook, after previously acknowledging in a letter to Reps. Markey and Barton that sharing a Facebook User ID could raise user concerns, subsequently considering sharing access to even more sensitive personal information such as home addresses and phone numbers to third parties?"
In response to a request for comment on the letter today, Facebook e-mailed a statement that made no direct reference to Markey and Barton's letter. "As an innovative company that is responsive to its users, we believe there is tremendous value in giving people the freedom and control to take information they put on Facebook with them to other websites," the statement said.
The statement stressed Facebook's commitment to ensuring that user information is shared only with the explicit consent of users and notes that its system of user permissions was designed in collaboration with privacy experts.
The Facebook state acknowledged the need for additional privacy enhancements before the new feature can be enabled. "Great people at the company are working on that and we look forward to sharing their progress soon."
Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at @jaivijayan, or subscribe to Jaikumar's RSS feed . His e-mail address is firstname.lastname@example.org.