If you use two-factor authentication (2FA) to secure your Facebook account, you likely, at some point, gave Facebook your phone number. 2FA adds an almost impenetrable layer of security to your Facebook account, since it requires you to enter a code sent via text message before logging in.
What you likely didn't know was that Facebook would use that data -- your phone number -- to target you with ads.
Following a report by Gizmodo that Facebook allows advertisers to target phone numbers, Facebook has confirmed the practice with TechCrunch, stating that it uses phone numbers provided for security purposes to target users with ads.
For example, a grocery store that collects phone numbers for rewards could, in theory, target that database of phone numbers on Facebook. Facebook would cross-reference the grocery store's list with its own database of phone numbers and serve ads to users associated with those numbers.
If you'd rather not get ads targeted to your phone number, it's a good idea to know how to take those digits off of your account settings right now. This guide will show you how to remove your phone number from your general profile and two-factor authentication (while providing an alternative to using a phone number).
app and select Settings & Privacy from the main drop-down menu. Select Settings and then Personal Information, which brings up your name, email address and phone number. Click Remove in the phone number field, which will prompt you to re-enter your Facebook password and then click Remove Phone in order to confirm the change. Look out for a confirmation email.
To remove your phone number from Facebook on your desktop, go to Settings under the main drop-down menu. Choose Your Facebook Information, and then choose View under Access Your Information. From there, go to Personal Information and choose Your Contact Information, where you'll see your mobile phone number(s). Click Remove, and then Remove Phone when you're asked if you're sure.
User note: Even if you've tried to remove your phone number from the Facebook app and it appears successful, you might want to also check from a desktop if the number is still there, as it was after I thought I had deleted it from my mobile. Either way you try to delete it, you should receive a confirmation email if you're successful.
(We reached out to Facebook for comment about this discrepancy and have not heard back.)
You may have also shared your phone number with Facebook to turn on two-factor-authentication (2FA), although the service stopped requiring the use of a phone number in May, so you may have used an authentication app such as Google Authenticator to turn on 2FA.
In order to remove your phone number from your 2FA setting on Facebook, you'll have to turn off 2FA and then turn it back on using an authentication app. On mobile, go to Settings from the drop-down menu, choose Security and Login and then go to Two-Factor Authentication to turn it off and on. Instead of using your phone number, you can use an authenticator app or a physical key as the second factor.
More on 2FA: When and how to use it.
Guidance: Why don't more people use 2FA?