California, April 18 -- Facebook Inc said said it 'unintentionally uploaded' the email contacts of 1.5 million new users since May 2016, without their knowledge or consent, a spokesperson for the networking giant said in a statement on Thursday.

In early April, Facebook was asking some users to enter their email passwords when creating new accounts, in order to verify their identities.

When the users entered their email passwords, they saw a message saying that Facebook was importing their contacts.

While the situation was initially unclear, Facebook said on Wednesday that this was how contacts were collected in order to improve ad targeting and new friends recommendations via expanding the network of social connections.

According to...