The FBI Indexes are a system used to track American citizens and other people by the Federal Bureau of Investigation (FBI) before the adoption by the FBI of computerized databases. The name signifies that the lists were originally made on paper index cards, compiled by J. Edgar Hoover before he became director of the FBI. The Index List was used to track U.S. citizens and others believed by the FBI to be dangerous to national security, and was subdivided into various divisions which generally were rated based on different classes of danger the subject was thought to represent. There is no indication the FBI stopped adding names onto its Index List before September 11, 2001.
After September 11, 2001, the date which the FBI folded its Index List into the Terrorist Screening Database (TSDB) is unknown, while the FBI consolidates the TSDB from other lists and manages its information. The TSDB is currently available to all U.S. national security agencies, while select information contained on the TSDB is forwarded to other nation states and international security agencies.