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Facebook's Phone Number Policy Could Push Users To Not Trust Two-Factor Authentication (vice.com)
An anonymous reader quotes a report from Motherboard: Using two-factor authentication, a security mechanism that requires a second step to login into an account other than the password, is widely considered an essential measure to protect yourself online. Yet, only a small percentage of people use this feature, mostly because it can be burdensome and it's rarely required by default, leaving users with the responsibility to turn it on. Now, Facebook may have given people yet another reason not to bother. Last week, Emojipedia founder Jeremy Burge warned in a viral Twitter thread that anyone could look him up on Facebook using his phone number, which he provided to the social network in order to enable two-factor authentication. What's worse, it looks like there's no way to completely remove your phone number that Facebook has collected. If you check your privacy settings, under "Who can look you up using the phone number you provided?" there are only three options: Everyone, Friends of friends, and Friends. "Everyone" is the default.
Even if you remove your phone number from the two-factor authentication settings page, nothing changes in the privacy settings, indicating Facebook still has your phone number. This screw-up, intentional or not, could discourage adoption of two-factor authentication, leaving people at risk of getting hacked. Facebook's decision to use phone numbers that were given to it for a specific security purpose for reasons other than security are a betrayal, and is training people more broadly that turning over more personal information to an internet company for security features could backfire. "Phone number is such a private, important security link," Zeynep Tufecki, a professor at the University of North Carolina, Chapel Hill, who has worked with dissidents and human rights activists, wrote on Twitter. "But Facebook will even let you be targeted for ads through phone numbers INCLUDING THOSE PROVIDED *ONLY* FOR SECOND FACTOR AUTHENTICATION. Messing with 2FA is the anti-vaccination misinformation of security."
Even if you remove your phone number from the two-factor authentication settings page, nothing changes in the privacy settings, indicating Facebook still has your phone number. This screw-up, intentional or not, could discourage adoption of two-factor authentication, leaving people at risk of getting hacked. Facebook's decision to use phone numbers that were given to it for a specific security purpose for reasons other than security are a betrayal, and is training people more broadly that turning over more personal information to an internet company for security features could backfire. "Phone number is such a private, important security link," Zeynep Tufecki, a professor at the University of North Carolina, Chapel Hill, who has worked with dissidents and human rights activists, wrote on Twitter. "But Facebook will even let you be targeted for ads through phone numbers INCLUDING THOSE PROVIDED *ONLY* FOR SECOND FACTOR AUTHENTICATION. Messing with 2FA is the anti-vaccination misinformation of security."
Training people to be skeptical of SMS-based 2FA is good, because forced number porting is so trivial. Due to social engineering or policy, it's far too easy to steal someone's phone number or its associated mobile codes. Furthermore, most people have it set up to show texts when their phone is locked, which undermines the value of verification codes if their phone is stolen. Dongles or even biometrics are superior. An NFC dongle you could slip in your phone case could be a good compromise.
Corruption is convincing someone that the selfless ideal is the same as their selfish ideal.