Facebook, privacy at risk if you’ve registered your phone number

New privacy problem for Facebook users: anyone who has your phone number could also find your profile. Here's why

Nth privacy flaw for Facebook and, this time, it also tastes like a hoax. If you gave Facebook your phone number for two-factor authentication (also known as 2FA), then virtually anyone could look up your mobile number and find your profile.

It sounds absurd, but that's just the way it is: if someone comes into possession of a phone number and doesn't know who it belongs to, they now have the ability to search for the owner by entering that number into the Facebook search bar. A real contradiction: you leave your number to Facebook so that no one can easily get hold of your data, and then a stranger can find out who you are if he gets hold of your number.

No chance to hide it

A major privacy loophole that, as TechCrunch reports, has been open for quite some time now even though no one had noticed it until now. In order for your phone number to be tracked and associated with your profile, all it takes is for someone with your number in their address book to allow Facebook to access your phone contacts. So you have almost no control over this because Facebook, at the moment, only allows you to limit who can find you from your phone number, leaving you the choice between Everyone, Friends, Friends of Friends. But you can't hide your number completely by setting "None".

What are the risks to your privacy

To give a practical example of the seriousness of this: if a friend of yours, who has your phone number, has given Facebook access to the address book and a third person, who is not in direct contact with you on social, somehow manages to find this number then they could look it up on Facebook and learn that the number belongs to you.

But this could also lead to dangerous data theft: if a hacker manages to steal your number, perhaps by hacking into a site where you have registered by providing your phone contact, he could search and find your Facebook profile and steal your identity. If then the hacker succeeds in piercing your friend's Facebook profile, then associating your number with your profile for him will be very easy.

In September 2018 another scandal broke out regarding how Facebook handles phone numbers: Zuckerberg's company was forced to admit that the phone numbers used for 2FA authentication were also used to send targeted advertisements to users. This latest case, then, seems like just more icing on the cake.