The military doesn't want to be the source of the next WikiLeak shit-storm, and is going to extreme means to ensure this—prohibiting the use of all disks and drives on its secret network, under penalty of court martial.
Like the Library of Congress' blanket ban against WikiLeaks access, this kind of draconian directive should only make things more difficult for the government, not protect it. Although the ban is applied only to machines on the military's internal, protected SIPRNet, it'll likely hamstring troops more than the Pentagon expects. Danger Room explains that "classified computers are often disconnected from the network, or are in low-bandwidth areas. A DVD or a thumb drive is often the easiest way to get information from one machine to the next," and quotes one military malcontent: "They were asking us to build homes before. Now they're taking away our hammers."