Safety monitoring systems ensure that a nuclear power plant doesn't begin to melt down by detecting temperature increases in reactor coolant water and fuel rods, along with other anomalous events in time to take preventive action. But on January 25, 2003, such systems shut down for nearly five hours at the Davis–Besse Nuclear Power Station in Oak Harbor, Ohio. Why? The "SQL Slammer" worm had infected the computers that run those systems via a contractor's computer. Fortunately, the plant had been shut down since 2002 to deal with another safety malfunction—a hole and cracks in its reactor.
This risk is not confined to power plants, nuclear or otherwise. The entire electrical grid is vulnerable to hacking, as proved by a test attack—dubbed Aurora—carried out by the Idaho National Laboratory. Nor is such hacking confined to the energy infrastructure. The U.S. Department of Defense, Google, bank ATMs and even the very microchips that make computing possible have all been hacked to nefarious ends.
On September 11, 2001, terrorists used airplanes themselves as weapons to bring down the Twin Towers of the World Trade Center in New York City as well as inflict severe damage on the Pentagon in Washington, D.C. Airplanes continue to hold a peculiar fascination for terrorists, although the bulk of such plots focus on detonating chemical explosives rather than commandeering and using the jets themselves.
As a result, airplanes remain the focus of many people's fears. But statisticians have calculated that the odds of being involved in a terrorist-related airplane death stand at more than one in 10,000,000, based on the past decade of air travel. For comparison, the odds of being struck by lightning are one in 500,000.
4. CHEMICAL WEAPONS
On March 20, 1995, members of a religious cult released poisonous sarin gas on five trains in the Tokyo subway system. The colorless, odorless nerve agent immediately caused sweating and muscle twitching, among other symptoms, some of it severe enough to kill 12 people by arresting their breathing. The cult, it was later discovered, also had in its arsenal hydrogen cyanide gas and other chemical weapons capable of inflicting even more massive casualties.
The idea of using nerve gas, poisons or other chemical weapons is not restricted to crazed Japanese cults. U.S. security officials have implicated the terrorist network al Qaeda in attempts to secure large quantities of castor beans. The beans are the primary ingredient in ricin, a white powder, which is deadly if inhaled or otherwise absorbed in minute quantities.
5. BIOLOGICAL WEAPONS
Beginning on September 18, 2001, envelopes arrived at the offices of Democratic Sens. Tom Daschle (S.D.) and Patrick Leahy (Vt.) in Washington, D.C., as well as media organizations such as ABC, CBS, NBC in New York City and American Media in Boca Raton, Fla. Each bore a powder—the spores of a bacterium that can cause a deadly infection known as anthrax. In fact, five people died from subsequent illnesses caused by the anthrax exposure.