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Facebook pages very much public, even when set as private

Privacy theater

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Facebook settings that are supposed to cloak user profiles can easily be bypassed to reveal the friends, pictures, and other attributes of users who have configured their accounts to be private.

The inability to keep profile pages private would seem to contradict Facebook's promise that "The settings you choose control which people and applications can see your information." In fact, profiles configured to be private remain viewable when manually browsing through the pages of users who are friends.

“My problem with this issue is actually how I found the bug,” said Justin E. Dian, a software developer who brought the setting bypass to the attention of The Register. “People I didn't want requesting me as friends kept somehow finding me and requesting friendship. I keep my Facebook security settings pretty much as tight as possible and I soon realized this is how they were finding me.”

The privacy settings were put in place following outcries that Facebook accounts spilled users' birthdates, friends, home towns, current location, and other information that could jeopardize their privacy. The new settings made it possible to share specific details with the world at large, a user's Facebook friends, friends of friends, or no one at all.

A Facebook spokesman said certain information, including the URL to the user's profile page, the user's picture, sex, and networks remain public no matter what settings are chosen.

“You can make it harder for people to find your profile in searches, but people may still be able to get to it in other ways (e.g., if they know your vanity URL or navigate there through a friend list or News Feed story),” the spokesman said. “The basic information that allows friends to find and connect with people is available to everyone and has no privacy settings.”

The spokesman didn't respond to repeated questions asking whether Facebook had plans to change the settings so the information was no longer public.

Profiles that have been designated as private are viewable when browsing a list of friends that includes the profile. These lists can be made available to the world at large, or to friends or friends of friends of the user. The lists include the profiles of all of the user's friends, even when they've told Facebook to keep information — including their friends — private.

The arrangement means that it's impossible to keep a Facebook profile completely private if it includes even a single friend whose friend list is accessible to others.

Dian said it probably wouldn't be hard to create a script that browses and records all of a user's friends of friends and then recursively browses and records each friend's friends who have lists set to be viewable by everyone or friends of friends. Search-engine spiders build detailed repositories of links in much the same fashion.

“Doing this, you could quickly create a very large database of people and have, at the least, the following information on all of these people, no matter their security settings: name, profile picture, networks and sex,” Dian said. “So in essence, while Facebook offers you security settings to only be searchable by your friends, it would be very easy for someone you are not friends with to have access to the previous information.”

Interestingly, using a name search to identify someone's friends won't list profiles that have been set to be private. But the same profiles continue to show up when you manually view the friends list. That means Facebook is technically correct that private profiles aren't searchable, even though they are in many cases easily found. ®

Mobile application security vulnerability report

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