The data leaks, which began in 2012, were the result of a technical glitch in its massive archive of contact information collected from its 1.1 billion users worldwide. Facebook users who downloaded contact data for their list of friends obtained additional information that they were not supposed to have.
The bug was first spotted last week and fixed within 24 hours. However Facebook did not publicly acknowledge the bug until Friday afternoon, when it published an "important message" on its blog explaining the issue. Writing in its bog, Facebook said that it had no evidence that this bug has been exploited maliciously and we have not received complaints from users or seen anomalous behavior on the tool or site to suggest wrongdoing.