Media stories about National Security Agency (NSA) surveillance pertain to the unauthorised disclosures of two different intelligence collection programs. These programs arise from provisions of the Foreign Intelligence Surveillance Act (FISA). However, they rely on separate authorities, collect different types of information, and raise different policy questions. This book provides background and issues for Congress with NSA surveillance leaks; provides a primer on some of the fundamental aspects of the security clearance process, using a "frequently asked questions" format; discusses criminal prohibitions on the publication of classified defence information; the legal framework of the protection of classified information; and practices and proposals of the protection of classified information by Congress.