should be consulted, TOP SECRET needs both an alarmed (with response) high-security filing cabinet with a combination lock; SECRET may relax the alarm requirement but still require the same high-security filing cabinet; CONFIDENTIAL may accept a regular filing cabinet, which has had a bracket welded to each drawer, and a strong steel bar run through the brackets and secured with a combination padlock. Other security measures might be closing drapes or blinds over the window of a room where classified information is handled, and might be photographed by an adversary at a height comparable to that of the window. No matter how physically secure a SCIF may be, it is no more secure than the people with access to it. One severe security breach was by a clerk, Christopher John Boyce, who worked inside the SCIF that held communications equipment and stored documents for a TRW facility in Redondo Beach, California. At this facility, among other sensitive programs, TRW built U.S. reconnaissance satellites for the National Reconnaissance Office and Central Intelligence Agency. Boyce stole documents and gave them to a drug dealer, Andrew Daulton Lee, who sold them to the Soviet KGB. Personnel security measures are as important as physical security. Counter-HUMINT measures might have detected the documents being transferred and taken to the Soviet Embassy in Mexico City. Personnel security Many of the greatest enemy penetrations of a country's secrets came from people who were already trusted by that government. Logically, if your service desires to find out your opponent's secrets, you do not try to recruit a person that would have no access to those secrets – unless the person you recruit gives you access to such a person. The general process of determining whether a person can be trusted is security clearance; the British term, used in many Commonwealth countries, is positive vetting. In the most sensitive positions, clearances are periodically renewed. Indications of possible compromise, such as spending patterns that are inconsistent with one's known income, are supposed to be reported to personnel security officers. Security clearance is a starting point, but, while respecting individual rights, a certain amount of monitoring is appropriate. Some of the worst US betrayals, of recent years, have been money-driven, as with Aldrich Ames and Robert Hanssen. Electronic reviews of financial records, raising flags if there are irregularities that need to be checked, may be among the least obtrusive means of