Business Insider reported that Facebook says it ‘unintentionally uploaded’ 1.5 million people’s email contacts without their consent.

Facebook harvested the email contacts of 1.5 million users without their knowledge or consent when they opened their accounts.

Since May 2016, the social-networking company has collected the contact lists of 1.5 million users new to the social network, Business Insider can reveal. The Silicon Valley company said the contact data was “unintentionally uploaded to Facebook,” and it is now deleting them.

How can this be unintentional? Facebook asked new accounts to enter their email passwords. That was already one big no-no. Then Facebook imports contacts from the email account. It actually shows a message saying it is importing the contacts, so that functionality is built in.

This highlights the importance of fencing your online accounts. I highly recommend that you don’t allow any third party to access your email account. Have a secondary account liked to your primary account, and if you really have to, allow access to the secondary account instead.