Introduction to Intelligence Studies94
Law Enforcement Operations
Although the NSA primarily carries out SIGINT internationally, like the
CIA, it cannot spy upon American citizens. Domestic intelligence and
terrorism wiretaps are administered by the FBI. e Foreign Intelligence
Surveillance Act (FISA), passed in 1978, regulates how domestic SIGINT
operations can be carried out (see Chapter 10, “Constitutional Mandates—
Overview of Executive, Legislative, and Judicial Roles”). A federal judge
must approve all FISA wiretaps. However, unlike criminal wiretaps, which
are approved by judges in the judicial district where the overhears occur,
the FISA court is located in Washington, D.C. e judges possess a security
clearance, which allows them t