None of these catastrophic scenarios has occurred, but they certainly cannot be ruled out. At a more modest level, hackers were able to destroy a blast furnace at a German steel mill last year.
这样的灾难性情景暂时尚未发生，但其可能性显然不能排除。在相对温和的水平上，黑客去年毁坏了一座德国钢厂的高炉。因此安全问题再简单不过：我们能否遏制这样的破坏行动？