The First World Hacker War
After last month's collision of an American spy plane and a Chinese jet, hackers in the United States and China began defacing Web sites on both sides of the Pacific. Then Chinese hackers, led by a group called the Honkers Union, declared war.

The White House's site was shut down for hours, computers at the California Department of Justice caught a virus and the eastern Ohio's Bellaire School District site played the Chinese national anthem while displaying China's fluttering red flag.

Most attacks involved cybergraffiti. American hackers tended to be insulting ("Slouching Tiger, Ridden Dragon" was slapped on a Chinese site); Chinese hackers, righteous ("We are ready to devote anything to our motherland, including our lives" was left on several American sites).
http://www.nytimes.com/2001/05/13/weekinreview/13BOXB.html?pagewanted=all