Earlier this month we saw the military ban the use of USB drives and other removable media. Apparently the virus outbreak that lead to this measure affected 75\% of all systems at the largest U.S. military base in Afghanistan. Details are still sparse, but both the LA Times and the U.S. News and World Report are reporting that the intrusion was severe enough to raise the INFOCON status, the information security equivalent of the DEFCON alert, and also necessitate the briefing of the president. We also don't know the source of the attack, but signs point to state rather than non-state actors, with the most popular contenders being either Russia or China.
Our military is dependent upon commodity desktops whose software shares an enormous amount of DNA with systems that sit on every workplace in the planet. These systems form the backbone of what is called network centric warfare. Hopefully the security that the military is planning for these systems is something less than... commodity.