Facebook collected the email contact lists of 1.5 million users without their knowledge or consent, Business Insider reports. Since May 2016, the social network said users' email contacts were “unintentionally uploaded to Facebook” while users were verifying their accounts on the website. The website reports the contacts were then used to “build Facebook's web of social connections” and to make friend recommendations. It's not clear if the contacts were used for ad-targeting purposes. “These contacts were not shared with anyone and we're deleting them. We've fixed the underlying issue and are notifying people whose contacts were imported,” a Facebook spokesperson wrote in a statement. “People can also review and manage the contacts they share with Facebook in their settings.” The company also said it would notify the 1.5 million users affected in the coming days. This comes after Facebook demanded some users hand over their email passwords in order to sign up for the website, among other privacy scandals that have plagued the company in recent years.