When Army Supply ordered X millions of rubber contraceptive and disease-preventing items, it had to be explained that they were used to keep moisture out of machine-gun barrels

A third sternly held rule was that five million perfectly normal, young, energetic, and concupiscent men and boys had for the period of the War Effort put aside their habitual preoccupation with girls. The fact that they carried pictures of nude girls called pin-ups, did not occur to anyone as a paradox. The convention was the law. When Army Supply ordered X millions of rubber contraceptive and disease-preventing items, it had to be explained that they were used to keep moisture out of machine-gun barrels - and perhaps they did.   

J. Steinbeck, Once there was a war (1959), 10