No one knows to what extent the U.S. has already engaged in cyber offensive attacks. In 2007, the Department of Homeland Security grabbed headlines when it released a video to raise alarm about vulnerabilities in the U.S. power grid. The video showed a simulated remote hacker attack against an electrical turbine which caused the turbine to spin out of control and collapse in a cloud of smoke.
The performance might easily have been inspired by a 1982 incident, in which the U.S. sabotaged the Siberian pipeline. After the U.S. learned from a Russian scientist that the Soviets were stealing data on U.S. technology, the CIA hatched a plot to insert a logic bomb into software it knew was headed to Russia to operate pumps, valves and turbines on the Siberian natural gas pipeline. The equipment worked fine initially, but at a pre-programmed time caused excessive gas pressure to build on the valves. The resulting explosion was captured by orbiting satellites and was "the most monumental non-nuclear explosion and fire ever seen from space," according to a former U.S. official who disclosed the incident in his 2004 memoir. Although there were no human casualties, the story might easily have had a different ending.