In June 2013, a series of documents leaked by former National Security Agency contractor Edward J. Snowden sparked an international debate over how much latitude to extend the NSA in its surveillance activities. It also raised questions concerning how deeply in bed American phone and Internet service providers have been with government agencies; although providers report being legally forced to cooperate and keep mum, some companies voluntarily entered into lucrative contracts to provide data to government agencies [sources: Savage; Schlesinger].
Beyond the NSA, the revelations also shone a light on the ways other agencies, which are governed by a hodgepodge of laws, regulations and oversight, use metadata to play connect the dots. Metadata is data about data; it doesn't involve content, but can include information such as dates, call durations and phone numbers [sources: Savage; Schlesinger].
The CIA, for example, paid AT&T $10 million per year to search its databases for phone numbers associated with terrorists overseas. Because AT&T blocked the information of any American who might have been on the receiving end of such a call, the contract did not violate the agency's restriction against gathering intelligence concerning the "domestic activities of U.S. persons." However, given that the FBI could subpoena such information and choose to share it with the agency, the lines appear more penciled-in than inked [source: Savage].