Facebook To 6M Users: We Moved Fast And Broke Your Privacy
Facebook, one of whose core principles is "Move fast and break
things," appears to have done just that with the contact
information of some six million users.  The social network
admitted that a complex bug involving the way it stores user
phone numbers and email addresses of its users may have
"inadvertently" exposed that information to other users.
Facebook used this information to make friend recommendations
and to make other recommendations smarter. For instance, it
would match email and phone data to make sure it didn't prompt
you to invite someone to Facebook if they were already on the
service; instead, it would prompt you to add such a person as a
friend.  Unfortunately, a bug in Facebook's software stashed
some of that phone and email data in other users' profiles.
Those who downloaded their profiles may have thus also saved off
contact information they otherwise wouldn't have had.  Here's
how Facebook describes the bug: