Facebook may have unintentionally uploadeds email contacts of up to 1.5 million users on its site, without their permission or knowledge, when they signed up for new accounts since May 2016. The tech giant said it used to have a step in the account verification process where some users had the option to confirm their email address and voluntarily import their email contacts onto the site. The feature was meant to help them find their friends more effectively and improve ads, Facebook said.”]