Facebook bug has exposed contact information of 6 million users. Facebook admitted on Friday that a bug had exposed private contact information of six million members.

The Facebook bug made contact information such as email addresses or phone numbers accessible to Facebook users downloading their account histories onto their own computers.

The security flaw is scaring some people away from Facebook. Facebook defenders say that the site is safe. Facebook has over 1 billion members; six million is a small percentage.

While the NSA has now been revealed to have been spying on Facebook users, this Facebook bug allowed users to have contact information of friends' private contact information.

The bug allowed "some of a person's contact information (email or phone number) to be accessed by people who either had some contact information about that person or some connection to them," Facebook said.

Facebook members who used the "Download Your Information" tool were accidentally sent phone numbers or email address of Facebook friends that were otherwise private.

The Facebook bug was found by a user, not someone on Facebook's security team.  Facebook offers a reward for anyone who can find a bug on the site.

Facebook said that the bug was fixed quickly, within a day, and that the bug was probably not used maliciously.