Just when you think the Cambridge Analytica scandal couldn't get any worse, it does. If you're one of those that took part in the quiz app This Is Your Digital Life, you not only shared your News Feed, timeline and posts, but your private messages too.
Speaking to Wired, Facebook confirmed to them that the app used a read_mailbox permission, and wasn't phased out completely until October 2015. Facebook phased out other sensitive permissions in April of 2015, but didn't phase out the read_mailbox one until alter that year.
Wired says that while users would have needed to give proper permission to the app in order for it to access their message inboxes, the request would have likely been hidden in with a bunch of other permissions that are requested. Basically, users may have missed it when “agreeing” to share their data.
Facebook says that a total of 1,500 people gave This Is Your Digital Life permissions to access their inboxes, but the total affected users is currently unknown.