On November 9, 2012, CIA Director David Petraeus (General, U.S. Army, retired) resigned over admission of an extra-marital affair. Notification of congressional intelligence oversight committees, traditionally provided by means of "Gang of Four" or "Gang of Eight" briefings, did not occur prior to the public announcement of the resignation. The requirement to report an event to a congressional intelligence committee depends on its classification as an "intelligence activity" or "significant anticipated intelligence activity." While an extra-marital affair itself is not classified as an "intelligence activity," the investigation by the Federal Bureau of Investigation (FBI) originated with the possible hacking of Director Petraeus's e-mail account, an act that had the potential of compromising national intelligence. Senator Dianne Feinstein, chairman of the Senate Select Committee on Intelligence, called for an investigation into why the FBI did not notify the oversight committees of the investigation of Director Petraeus over what she considers an "operationally sensitive matter." The "Gang of Four" intelligence notification procedure has no basis in statute. Nor is such a procedure referenced in the rules of either of the two congressional intelligence committees. Rather, this particular notification procedure could be reasonably characterized as a more informal notification procedure that, over time, has come to be used by the executive branch, and has been generally accepted by the leadership of the intelligence committees, to provide limited notification of particularly sensitive intelligence activities to the committees' chairmen and ranking Members. The use of Gang of Four notifications pre-dates the establishment of the congressional intelligence committees in the mid-1970s. Initially, such limited notifications were used to inform relevant congressional committee leadership of especially sensitive intelligence matters, including both covert action and intelligence collection programs. Observers commenting on such notifications used during this time period characterized them as being oral and often cursory, and being limited to committee chairmen and ranking Members and one or two senior staff members. In 1980, when Congress approved the new "Gang of Eight" notification procedure for particularly sensitive covert action programs, use of the Gang of Four process came to be generally limited to notifying the committee leadership of sensitive non-covert action intelligence programs. In 1980, Congress also adopted statutory language requiring that, except for covert action notifications, which are governed by a separate set of statutory requirements, the intelligence community is obligated to keep the congressional intelligence committees fully and currently informed of all intelligence activities and furnished with any information or material concerning such intelligence activities. Congress conditioned these two reporting requirements on the need to protect from unauthorized disclosure classified information relating to sensitive intelligence sources and methods or other exceptionally sensitive matters. Report language stated: The Administration recognizes that the intelligence oversight committees of the House and Senate are authorized to receive such information. However, it is recognized that in extremely rare circumstances a need to preserve essential secrecy may result in a decision not to impart certain sensitive aspects of operations or collection programs to the oversight committees in order to protect extremely sensitive intelligence sources and methods. [emphasis added] In 1991, Congress adopted new but similar language with regard to the protection of sources and methods, adding in statute the phrase "other exceptionally sensitive matters." Doing so, according to accompanying report language, would more accurately reflect and was intended to have the same meaning as the legislative history of the 1980 statutory change. The report language stated that the added phrase: is intended to refer to other extremely sensitive categories of classified information such as information concerning the operational details of military deployments, and extraordinarily sensitive diplomatic contacts , which the intelligence committees do not routinely require to satisfy their responsibilities. [emphasis added] In the wake of congressional investigations undertaken in the mid-1970s that documented a pattern of misconduct on the part of U.S. intelligence agencies, Congress tightened its oversight of the intelligence community by establishing intelligence committees in the House and Senate that were to be exclusively devoted to intelligence oversight. Until these two committees were established, Congress's oversight of the intelligence agencies, although more assertive than is generally understood, particularly insofar as the Central Intelligence Agency (CIA) was concerned, was generally viewed as limited and informal. That approach began to change in the face of the revelations of wrong-doing by the intelligence community. In the resolutions establishing the intelligence committees, Congress set out several new obligations that, at least in the case of the Senate, emphasized certain executive branch obligations to keep the two new intelligence committees fully and currently informed of all intelligence activities, including both collection and covert action programs. Although legally non-binding, the "sense of the Senate" resolution establishing the Senate committee also stated that the intelligence agencies should keep the committee informed of "any significant anticipated activities," and provide such information as may be requested by the committee relating to matters within its jurisdiction. Although the House did not include similar language in its resolution, both committees took the position that they were "appropriate committees" for the purposes of receiving notice of covert actions, a position to which the Administration of President Jimmy Carter acquiesced. Despite the Senate's directive that the Senate's new intelligence committee be kept fully and currently informed of all intelligence activities, the executive branch continued its practice of limiting notification of certain sensitive intelligence activities, including covert and collection operations, to the committees' chairmen and ranking Members—the Gang of Four—with the apparent acquiescence of the committees' leadership. According to one account, the committee's chairman, Senator Birch Bayh, said: There were a couple of other areas where the president wouldn't tell the entire committee. He let me know but not the entire committee. I suggested to Goldwater we keep it to ourselves. Barry concurred. There were a couple of others we decided to tell to the entire committee. According to this same account, there were other sensitive operations about which the committee and its chairman received no notification. Gang of Four members reportedly continue to keep the contents of sensitive briefings to themselves, although on certain occasions, the chairman and ranking Member of the House Intelligence Committee reportedly have agreed to share the information with their respective party leaders. According to at least one Gang of Four member, the choice to do so is not always the lawmakers' to make. Representative Silvestre Reyes, a former chairman of the House Intelligence Committee, reportedly said that, during the Administration of President George W. Bush, he was unable to have legal counsel or subject matter experts in attendance during such restricted briefings, leaving the committee unable to conduct oversight. "We were at a huge disadvantage, because [the administration and the intelligence community] called the shots," Reyes reportedly stated. Although Senate Intelligence Committee Chairman Bayh appeared to accept the practice of restricted Gang of Four notifications, he reportedly was furious when he learned President Carter had not informed him in advance of the 1980 covert efforts to rescue U.S. hostages held in Iran because of concerns over operational security and the risk of disclosure. Director of Central Intelligence Stansfield Turner briefed the full intelligence committees, but only after the operations had been conducted. Bayh expressed his concern that the executive branch's action reflected a distrust of the intelligence committees. "It would have been so easy to tell us," he was quoted as saying. "Any leaker of that information would be hung up by his thumbs. I expressed my anger to Carter about not informing us. Carter had a thing about not being able to trust the committee." Other members of the committee, however, apparently were quite sympathetic to the Administration's concerns and expressed their understanding of the demands of secrecy and the subsequent decision to withhold prior notification. One, a senior Republican on the committee, was quoted as saying, "The more people you tell, the more danger there is of losing life. I say: 'To hell with the Congress.'" Despite the overall sympathy shown for President Carter's position by other members of the intelligence committees, Senator Bayh suggested that future administrations could address disclosure concerns by notifying a more limited number of members, a special subcommittee of five or seven, "so that at least somebody in the oversight mechanism would know.... If oversight is to function better, you first need it to function." This general sentiment appeared to prevail. Later in 1980, Congress approved in statute the new Gang of Eight notification procedure. Henceforth, the intelligence committees' leadership, the Speaker and minority leader of the House, and Senate majority and minority leaders, were to be provided prior notice of particularly sensitive covert action programs if the President determined that limited access to such programs was essential to meet extraordinary circumstances affecting vital U.S. interests. At that time, neither the statute nor accompanying report language further defined what would constitute "extraordinary circumstances affecting vital U.S. interests," although in 1991, Intelligence Conference Committee Conferees stated that the Gang of Eight notification procedure should be invoked when "the President is faced with a covert action of such extraordinary sensitivity or risk to life that knowledge of the covert action should be restricted to as few individuals as possible." Conferees also indicated that they expected the executive branch to hold itself to the same standard by similarly limiting knowledge of such sensitive covert actions within the executive. Gang of Four and Gang of Eight notifications differ in several ways. A principal difference is that the Gang of Four notification procedure is not based in statute, as previously mentioned, but rather is a more informal notification process that generally has been accepted by the leadership of the intelligence committees over time. By contrast, the Gang of Eight procedure is provided for in statute, and imposes certain legal obligations on the executive branch. For example, when employing this particular notification procedure, the President must make a determination that vital U.S. interests are at stake if a notification is to be restricted to the Gang of Eight and provide a written statement setting forth the reasons for limiting notification to the Gang of Eight, rather than notifying the full membership of the intelligence committees. The President also is required to provide the Gang of Eight advance notice of the covert action in question, although the statute also recognizes the President's constitutional authority to withhold such prior notice altogether.