Deputy Defense Secretary William Lynn unveiled a new U.S. defense strategy that designates cyberspace as an “operational domain.” Like sea, air and land, U.S. forces will now practice, train and prepare to defend the country against attacks that take place online. To emphasize the necessity of the new strategy, Lynn revealed information about a recent cyber attack in which 24,000 files were stolen from a U.S. defense contractor. Lynn indicated that the US is under constant cyber attack. The Defense Department operates more than 15,000 computer networks and 7 million computers at hundreds of installations around the world. The department’s networks are probed millions of times a day and penetrations have compromised huge amounts of data, Lynn said. Economic losses from theft of intellectual property and information from government and commercial computers are estimated at over $1 trillion. Lynn outlined a plan that cordons off government networks and requires more robust security and authentication. The Defense Department also plans to go on the offensive retaliating against those that attack U.S. networks and computers.