Defcon is the one of the oldest and largest continually running hacker conventions, started by The Dark Tangent. According to their own FAQ, Defcon started as a party for members of “Platinum Net,” a Fido protocol-based hacking network out of Canada. Fido was one of the protocols used to store and forward information before the Internet was pervasive and popular. People used it to create ad-hoc networks that stored and forwarded files and messages across the world.
Back in the late 1980s and early ’90s, the phone company did not offer unlimited service. They charged significant amounts of money to make long distance calls. Many of the kids who grew up on Commodores, Apples, Amigas, Spectrums and PCs traded cracked/pirated games (warez), traded demos, chatted, and wanted to explore.