A controversial surveillance law is set to expire at midnight after a dizzying few weeks of failed efforts by Congress and the White House to renew it and prevent a loss of access to critical national security information. It is the first lapse of the spy program, known as Section 702 of the Foreign Intelligence Surveillance Act (FISA), since it was passed into law in 2008. It enables U.S. intelligence agencies to gather without a warrant the digital communications of foreigners overseas.