You might have used the two-factor authentication (2FA) feature on apps like Facebook, WhatsApp and Instagram. It helps users to secure their accounts across the web.

But the same isn’t the case with Facebook’s two-factor authentication. Users complained on social media that the phone number they used on Facebook to secure their account with 2FA can also be used by anyone to look up their profile.

Additionally, Facebook doesn’t give you an option to opt out, Tech Crunch reported.

Last year, Facebook admitted that the platform was using phone numbers to target users with ads. Tech expert Jeremy Burge posted on Facebook criticising the platform for letting users look up random profiles.