Facebook Exposed 6 Million Users' Contact Info

Facebook accidentally shared 6 million users' email addresses or telephone numbers due to a software bug, the company announced Friday.

The breach was caused by an unfortunate combination of Facebook's "People You May Know" and "Download Your Information" features. "People You May Know" offers friend suggestions based in part on other users' uploaded contact lists or address books; "Download Your Information" offers a downloadable version of your Facebook Timeline archive

When some users downloaded their Facebook archives with "Download Your Information," the archive included contact information for second-tier connections with whom Facebook thought those users might want to connect but who hadn't yet received or approved a friend request from that user. Translation: Data breach.