March 26, 1999
The first e-mail virus to cause widespread damage and one of the fastest spreading viruses in history, Melissa was released into the wild on an early Friday morning and within three days would infect between 100,000 and 250,000 computers around the world. Targeting Microsoft Word and Outlook, the virus did not directly cause any damage, but the sheer volume of e-mail that it generated crashed many corporate *cough* Microsoft *cough* e-mail servers.
The malware first showed up on the alt.sex usenet group and was apparently named by its creator, David L. Smith, after an exotic dancer. He was arrested a few days later on April 1st, 1999 and accused of causing $80 million worth of damages. He pleaded guilty and was sentenced to 20 months in prison and a $5,000 fine.