Update: Facebook has decided to rethink its strategy on this, and has temporarily stopped granting access to phone number/address info. More here.
Original Article: Over the weekend, Facebook updated its developer blog with a post subtly titled: "Platform Updates: New User Object fields, Edge.remove Event and more." Perhaps a more fitting title would have been, "We're Giving Developers Access to User Mobile Phone Numbers and Home Addresses."
Why would that be a more fitting title? Because that's the first update explained in the post, and most likely the one people will be most interested in (and not just developers).
"We are now making a user's address and mobile phone number accessible as part of the User Graph object," wrote Facebook's Jeff Bowen. "Because this is sensitive information, we have created the new user_address and user_mobile phone permissions. These permissions must be explicitly granted to your application by the user via our standard permissions dialogs."
You know, that standard request for permission that looks something like this (which you read thoroughly every time right?):
"Please note that these permissions only provide access to a user's address and mobile phone number, not their friend's addresses or mobile phone numbers," says Bowen.
So, now any site or app that uses Facebook integration (there are a few of them out there) can get direct access to your phone number and home address if you provide that info to Facebook.
While there will no doubt be plenty of privacy-related outcries over this, it's up to you if you want to provide that information. Just know that if you do, it's available to third parties everywhere, so don't be surprised if you log into sites with your Facebook account, and start getting marketing calls and mail that you didn't get before.