20th Anniversary of the first PC virus.

On January 19, 1986, the first PC virus — Brain — was detected. It was virtually harmless, and the Pakistani creators claim that it was only intended to protect their copyrights. (They did, after all, include their own address and phone number in the machine code.) In the past 20 years, though, both creating viruses and destroying them have become billion-dollar industries. [from MetaFilter.com]