The Ministry of Defense and the U.S. intelligence services purchased on the "gray" market, the most expensive, so-called vulnerability "zero-day" - critical "holes" in the software, which was not previously known computer experts. Since 0day-protection against vulnerabilities have not yet invented, then you can use them to spy on citizens, as well as a "cyber war" against other countries or competing companies.
Cost dangerous "holes" ranges from 50,000 to 100,000 dollars. Using just this vulnerability 0day-built "industrial" virus Stuxnet, has infected in June 2010 computers at the Bushehr nuclear power plant in Iran.