The U.S. Army Tactical Command and Control System (ATCCS) is a new system that will provide combat commanders at brigade, division and corps headquarters with a battlefield Internet. A team of army troops was turned loose to see if there were ways to crash this new communications system. It turns out that ATCCS, as it is currently configured, is quite vulnerable. The key weakness is the MSE (mobile subscriber equipment) transmitters. The truck mounted MSE have to be set up on the high ground, because they transmit their FM, and other electronic signals, in a straight line (line of sight in milspeak). The MSE is thus easy to find, even if attempts are made to camouflage it with nets or vegetation. Its also possible to spot an operating MSEs electronic signals. Once you know where the MSEs are, its possible to destroy them. If you havent got artillery, rockets, commandos or warplanes to destroy MSEs, its also possible to jam them. This can be done even if you dont have jammers that can hit the exact frequencies the MSE uses (this is done by exploiting the harmonics of other frequencies.) The army, obviously, isnt talking about what solutions it has for these problems, but at least they know they have a problem. In the past, such vulnerabilities were often discovered in combat, where people got killed because of it.