On Sunday, a hacker threatened to dump the contact information of thousands of FBI and Department of Homeland Security employees online. Then on Monday, the hacker made good on said threat and released the information, first from the DHS, then from the FBI. The hacker who released the information claimed to have had access to up to 200GB further of information, meaning there could be plenty more releases to come in the days ahead. So how did a person break into the systems of two of America's most high-profile agencies? A phone call, it appears.