Do NSA's Bulk Surveillance Programs Stop Terrorists?

An in-depth analysis of 225 individuals recruited by al-Qaeda or a like-minded group or inspired by al-Qaeda’s ideology, and charged in the United States with an act of terrorism since 9/11, demonstrates that traditional investigative methods, such as the use of informants, tips from local communities, and targeted intelligence operations, provided the initial impetus for investigations in the majority of cases, while the contribution of NSA’s bulk surveillance programs to these cases was minimal.

The controversial bulk collection of American telephone metadata, which includes the telephone numbers that originate and receive calls, as well as the time and date of those calls but not their content, under Section 215 of the USA PATRIOT Act, appears to have played an identifiable role in initiating, at most, 1.8 percent of these cases.