The Air Force recently issued an order prohibiting personnel from using “removable media on all systems, servers, and stand alone machines residing on SIPRNET,” according to a document obtained by Wired. The penalty for not complying with the order is a court-martial.
You may recall that SIPRNET is the same computer network from which Army intelligence analyst Bradley Manning copied thousands of internal war documents to a blank CD simply labeled “Lady Gaga” earlier this year before giving the information to WikiLeaks. (More on TIME.com: Afghan Leaks: Is the U.S. Keeping Too Many Secrets?)
Apparently a ban on writeable media devices such as portable hard drives had been in effect until February of this year in response to a computer virus that had made its way “onto hundreds of thousands of computers” two years earlier, according to Wired. Shortly after the ban was lifted, Manning began collecting the documents that would eventually find their way to WikiLeaks.
Aside from the resurrected ban on portable storage devices, over half of the military’s computers have recently been connected to a networked security system that protects machines from known cyber threats and can apparently detect “anomalous behavior,” according to Wired.
The challenge for military personnel that use classified machines is that, for security purposes, many of the computers aren’t connected to one another. When files need to be transferred between computers, the easiest way to do so has been with a thumb drive or a writeable disc.
One could also make the argument that certain military personnel may be carrying storage devices without even knowing it—several cell phones and portable MP3 players feature thumb drive-like functionality, for instance, whether their owners realize it or not.
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