The Washington Post reports that Facebook said contact information for as many as 6 million of its users may have been exposed through a bug recently reported to the company’s security team. In a company blog post written by Facebook’s security team, the social network said that the flaw allowed some people to see users’ e-mail addresses or phone numbers without permission. “When people upload their contact lists or address books to Facebook, we try to match that data with the contact information of other people on Facebook in order to generate friend recommendations,” the company said in the post. “Because of the bug, some of the information used to make friend recommendations and reduce the number of invitations we send was inadvertently stored in association with people’s contact information as part of their account on Facebook.”