As it turns out, the email contacts of 1.5 million people have been uploaded to Facebook through this method.
Before this date, new users were asked if they wanted to verify their identity via their email account.
"We've fixed the underlying issue and are notifying people whose contacts were imported", Facebook said, adding that the contacts weren't shared with anyone and are being deleted.
A person holds a smartphone with the Facebook logo in front of displayed "top secret" and "email" words, in this picture illustration taken December 6, 2018.
The company has seen a string of gaffes involving users' sensitive information in recent years.
Credit: Denys Prykhodov/ShutterstockFacebook admitted that it has uploaded the contact lists of 1.5 million users since 2016 without their consent, Business Insider reported today. And if the user did enter the email password within Facebook, they would get a message saying Facebook is importing their contacts.
"Last month we stopped offering email password verification as an option for people verifying their account when signing up for Facebook for the first time", a Facebook spokesperson said.
But in May 2016, Facebook said it changed the feature to disable automatic contact upload and removed the text stating that a user's contacts would be automatically uploaded at the same time they granted access to their email account so they could verify their account.
The spokesman said it took nearly three years for Facebook to find the problem, which affects users who signed up since the change was made. This is related to the discovery in early April that users signing up to Facebook using certain email account providers, such as Yandex or GMX, were being asked for their email password as part of the verification process. The feature, which allows Facebook to automatically log in to a webmail account to effectively click the link on an email verification itself, was apparently meant to smooth the workflow for signing up for a new account. And don't worry: Deleting your contacts from Facebook will not delete your Facebook friends.