https://www.archives.gov/federal-register/codification/executive-order/12333.html
"HOW DOES THE [C_A] COLLECT INTELLIGENCE?"
Part 2
Conduct of Intelligence Activities
2.1Need. Accurate and timely information about the capabilities, intentions and activities of foreign powers, organizations, or persons and their agents is essential to informed decisionmaking in the areas of national defense and foreign relations. Collection of such information is a priority objective and will be pursued in a vigorous, innovative and responsible manner that is consistent with the Constitution and applicable law and respectful of the principles upon which the United States was founded.
2.2Purpose. This Order is intended to enhance human and technical collection techniques, especially those undertaken abroad, and the acquisition of significant foreign intelligence, as well as the detection and countering of international terrorist activities and espionage conducted by foreign powers. Set forth below are certain general principles that, in addition to and consistent with applicable laws, are intended to achieve the proper balance between the acquisition of essential information and protection of individual interests. Nothing in this Order shall be construed to apply to or interfere with any authorized civil or criminal law enforcement responsibility of any department or agency.
2.3Collection of Information. Agencies within the Intelligence Community are authorized to collect, retain or disseminate information concerning United States persons only in accordance with procedures established by the head of the agency concerned and approved by the Attorney General, consistent with the authorities provided by Part 1 of this Order. Those procedures shall permit collection, retention and dissemination of the following types of information:
(a) Information that is publicly available or collected with the consent of the person concerned;
(b) Information constituting foreign intelligence or counterintelligence, including such information concerning corporations or other commercial organizations. Collection within the United States of foreign intelligence not otherwise obtainable shall be undertaken by the FBI or, when significant foreign intelligence is sought, by other authorized agencies of the Intelligence Community, provided that no foreign intelligence collection by such agencies may be undertaken for the purpose of acquiring information concerning the domestic activities of United States persons;
(c) Information obtained in the course of a lawful foreign intelligence, counterintelligence, international narcotics or international terrorism investigation;
(d) Information needed to protect the safety of any persons or organizations, including those who are targets, victims or hostages of international terrorist organizations;
(e) Information needed to protect foreign intelligence or counterintelligence sources or methods from unauthorized disclosure. Collection within the United States shall be undertaken by the FBI except that other agencies of the Intelligence Community may also collect such information concerning present or former employees, present or former intelligence agency contractors or their present or former employees, or applicants for any such employment or contracting;
(f) Information concerning persons who are reasonably believed to be potential sources or contacts for the purpose of determining their suitability or credibility;