See update below Facebook will be moving forward with a controversial plan to give third-party developers and external websites the ability to access users' home addresses and cellphone numbers in the face of criticism from privacy experts, users, and even congressmen.

Facebook quietly announced the new policy in a note posted to its Developer Blog in January. It suspended the feature just three days later following user outcry, while promising that it would be "re-enabling this improved feature in the next few weeks."

In response to a letter penned by Representatives Edward Markey (D-Mass.) and Joe Barton (R-Texas) expressing concern over the new functionality, Facebook reaffirmed that it will be allowing third parties to request access to users' addresses and phone numbers.

Facebook noted that it is considering implementing controls that would more explicitly highlight the personal nature of the information being transmitted to applications and explained it is "actively considering" whether to restrict users under 18 years old from sharing their contact information with third-party developers.

"We expect that, once the feature is re-enabled, Facebook will again permit users to authorize applications to obtain their contact information," Facebook's Marne Levine, vice president of global public policy, wrote in the letter to Reps. Markey and Barton. "[H]owever, we are currently evaluating methods to further enhance user control in this area."

Facebook has attempted to tread a fine line with regard to privacy issues even as it has continuously pushed users to share more information, both on Facebook and beyond the social network.

The plan to open up users' address and phone numbers to third-party sites and services marks the latest frontier in Facebook's often controversy-fraught efforts to encourage users to be more liberal in sharing their data and online activity.

Even if the revamped feature were to include improved notifications and protections for minors, privacy experts warn the feature could imperil users' personal information and increase their risk of being targeted by scams, spam, and identity thieves.

Though Facebook prohibits applications from selling users' information or sharing it with advertisers and data brokers, malicious, rogue apps spreading phishing scams and other ruses are not uncommon on the social network. With just a few errant clicks, an unsuspecting user could potentially hand over her home address to a scammer peddling diet cures or free iPads in an effort to compile credit card data and other personal information.

"[Scammers] might be able to impersonate you if they had your phone number," said Norman Sadeh-Koniecpol, a professor at the Carnegie Mellon School of Computer Science. "They're saying, 'Please give us your phone number,' but they're not telling you whether they'll share it or whether they'll sell it or use if for malicious purposes. In fact, you don't know who you're dealing with."

Others are concerned with what they see as Facebook's willingness to change the rules of play--first encouraging people to share personal information with a more limited group of friends, then allowing that data to be accessed in new, unexpected ways.

"People never thought when they were posting this data [such as their phone numbers] that it would be accessible to anyone but friends. There's a real mismatch of expectations around that," said Mary Hodder, chairman of the Personal Data Ecosystem Consortium. "Even if Facebook comes back with new protections, they're still saying, 'Hey, get over it, your data is public.' I feel badly for users that Facebook's approach is 'You give us anything and it's all fair game.'"

Despite the social network's intentions to make addresses and phone numbers accessible to developers, Rep. Markey offered Facebook measured praise for its response, while stressing the necessity of protecting younger users.

"I'm pleased that Facebook's response indicated that it's looking to enhance its process for highlighting for users when they are being asked for permission to share their contact information," Rep. Markey said in a statement. "I'm also encouraged that Facebook is deciding whether to allow applications on the site to request contact information from minors. I don't believe that applications on Facebook should get this information from teens, and I encourage Facebook to wall off access to teen's contact information if they enable this new feature."

UPDATE: Facebook has contacted The Huffington Post with the following statement:

Despite some rumors, there's no way for other websites to access a user's address or phone number from Facebook. For people that may find this option useful in the future, we're considering ways to let them share this information (for example to use an online shopping site without always having to re-type their address). People will always be in control of what Facebook information they share with apps and websites.