Barton Gellman

During the morning rush hour on March 20, 1995, the Japanese cult Aum Shinrikyo placed packages on five subway trains converging on Tokyo's central station. When punctured, the packages spread vaporized Sarin through the subway cars and then into the stations as the trains pulled in.

Stuxnet, a computer worm reportedly developed by the United States and Israel that destroyed Iranian nuclear centrifuges in attacks in 2009 and 2010, is often cited as the most dramatic use of a cyber weapon.