_Security supervision_ can be exercised by monitoring facilities: that is, the security officers can equip themselves with a good radio receiver and listen to the broadcasts without ever meeting the broadcasters. A critical frame of mind on the part of such security personnel is desirable. Unlike liaison officers, they need not be cooperative. Since their criticism applies after the operation, they can afford to apply rigorous standards. (During most of 1942 and 1943, no one in Washington had any idea of what actually _went out_ from San Francisco. The civilians who broadcast to Japan received elaborate orders to do this and to do that, but the Washington policy-makers did not know what was going on the air. On one occasion, the civilian propaganda broadcasters told the Army in Washington that the information was too highly classified to be released or circulated. The result was that Army and Navy found out what OWI was doing by receiving reports from listeners in the Pacific.) Security liaison can check propaganda output in the process of transmission; security supervision can check the output after it goes on the air, and can transmit through channels recommendations for punitive or corrective action. The final military connection should exist (for an all-military psychological warfare group) in the person of a responsible commanding or executive officer. For a civilian group functioning under military control the military connection should lie in the hands of an officer capable of watching a great deal and of saying little. Attempts by security to act as propagandists have been found to be as disastrous as the efforts of operators to get along without security. =Media Limitations.= Psychological warfare should not broadcast into areas in which radio sets are unknown. Psychological warfare should not drop books to illiterates. These rules seem obvious but they have often been violated. Psychological warfare should not assume that an extensive news or morale campaign is going to achieve the desired results unless there is trustworthy intelligence to the effect that propaganda is getting through.