Electronic surveillance represents the most important foreign intelligence collection tool available to the U.S. government. Correspondingly, the ability to surveil constitutes one of those activities most susceptible to abuse by a government against its citizens. In the U.S., the governments use of electronic surveillance is highly regulated and can be conducted for only two purposes: law enforcement, which is undertaken by both federal and state governments; and foreign intelligence collection, which is an exclusively federal government function conducted pursuant to a single authority - the Foreign Intelligence Surveillance Act or “FISA. FISA governs not only electronic surveillance but the use of physical searches, pen registers, trap and trace devices, and business records collection to acquire foreign intelligence. It permits surveillance and other intrusive activities in the United States both with, and in limited circumstances, without a warrant. It covers virtually every major intelligence collection effort used by the United States and constitutes the most important intelligence authority available in the war against terror. This course will cover important FISA surveillance provisions up for congressional reauthorization by the end of 2019, as well as the significant FISA coverage in the media related to the use of FISA surveillance in the FBIs counterintelligence investigation related to the 2016 presidential election.