Facebook has created a new feature called Instant Verification that is designed to help Android users login to online accounts and services without all the fuss of confirming their email address or dealing with a verification code sent by SMS. The feature hinges on Android users registering with the same mobile phone number thats attached to the Facebook mobile app they already have open and running on their Android device. Facebook no doubt believes its new feature will only strengthen the 97% conversion rate of Account Kit on sign-ups. But as companies like Facebook begin to broaden the opportunities for mobile account creation, they also raise a number of security concerns.”]
Source: https://grahamcluley.com/facebook-instant-verification/