When Facebook introduced two-factor authentication to identify itself in the social network, one of the requirements was to enter the telephone number. This makes sense, since two-step authentication requires a form of extra contact to verify the user, and in many cases, this form is usually the phone number, although sometimes you can also choose an email.
“Facebook permanently links users’ accounts to their phone number.”
But Facebook has not only used users’ phone numbers to allow two-step authentication. The social network admitted last year that it used the telephone number of the users for the personalization of advertising. But there is still more, since the telephone number can be used by anyone to find user profiles in the social network.
This information has begun to spread following a tweet that ensures that it is impossible to completely disable this function. And it is true, since Facebook allows you to restrict the search of a profile by phone number to three groups of people: everyone, friends of friends, and only friends, but it is impossible to deactivate this function at all.
Currently it is no longer mandatory to enter the phone number to activate two-step authentication, so users who want to avoid giving more information than necessary to Facebook can use apps to achieve the same effect. But at the moment, those who registered with their phone, can not recover that privacy.
It is ironic that, in order to better protect users’ accounts, they are in a vulnerable position with regard to their privacy. Maybe over time Facebook allows its users to completely hide their phone number, but seeing the plans of the company to merge the social network with WhatsApp, at least as far as computer systems and databases are concerned, seems unlikely .