This is a story about how technology may some day destroy the world. The last century had threats that could only be achieved by large establishments (ie, countries), such as nuclear, biological, and chemical attacks. The coming century has new threats, which can be achieved by much smaller organizations. The threats include nanotechnology, genetics, and robotics. The threats still have the means to render the world uninhabitable, but are purely technological, they don't require ultra-sophisticated techniques.
It's written by Bill Joy. He was an absolute genius, a key figure in the making of Unix, Solaris, and Java. He also wrote vi.
In any case, the article is very long, but it's definitely worth reading fully:
http://www.wired.com/wired/archive/8.04/joy.html