"This Appendix, pursuant to the Committee's mandate under Senate Resolution 21, focuses on the use of informants in FBI intelligence investigations who are recruited, paid and directed by Bureau Special Agents. The Committee did not examine the use of informants in FBI criminal investigations nor did the Committee examine instances of the 'walk-in' who volunteers information to the FBI on a one-time basis. As discussed in more detail below, paid and directed intelligence informants are extensively used in FBI domestic intelligence investigations of groups and individuals. These intelligence informants are the subject of this Appendix."
Supplementary Detailed Staff Reports on Intelligence Activities and the Rights of Americans - Book III (1976)