Facebook says it has harvested email contact lists for 1.5 million users since May 2016. The social network said the situation was unintentional and that somehow, it just happened. A security researcher earlier in April noticed Facebook was asking some not all, curiously new users to provide their email passwords when they signed up for a Facebook account, if they used certain email platforms, like Yandex or GMX. The firm did not ask for consent or permission to do so, either. The problem was a result of a design change, a spokesperson said.
Source: https://threatpost.com/facebook-harvests-email-contacts/143915/