DEF CON (also written as DEFCON or Defcon) is one of the world's largest annual hacker conventions, held every year in Las Vegas, Nevada. The first DEF CON took place in June 1993.
Many of the attendees at DEF CON include computer security professionals, journalists, lawyers, federal government employees, security researchers, and hackers with a general interest in software, computer architecture, phone phreaking, hardware modification, and anything else that can be "cracked." The event consists of several tracks of speakers about computer- and cracking-related subjects, as well as social events and contests in everything from creating the longest Wi-Fi connection and cracking computer systems to who can most effectively cool a beer in the Nevada heat. Other contests include lockpicking, robotics-related contests (discontinued), art, slogan, coffee wars (not currently running), scavenger hunt and Capture the Flag. Capture the Flag (CTF) is perhaps the best known of these contests. It is a hacking competition where teams of crackers attempt to attack and defend computers and networks using certain software and network structures. CTF has been emulated at other cracking conferences as well as in academic and military contexts.
Conference founder Jeff Moss contends that the quality of submitted talks has diminished since DEF CON's inception.
Since DEF CON 11, fundraisers have been conducted for the Electronic Frontier Foundation. The first fundraiser was a dunk tank and was an "official" event. The EFF now has an event named "The Summit" hosted by the Vegas 2.0 crew that is an open event and fundraiser. DefCon 18 (2010) hosted a new fundraiser called MohawkCon. In 2010, over 10,000 people attended DEF CON 18.
Federal law enforcement agents from the FBI, DoD, United States Postal Inspection Service, and other agencies regularly attend DEF CON.
DEF CON was also portrayed in the The X-Files episode "Three of a Kind" featuring an appearance by The Lone Gunmen. DEF CON was portrayed as a United States government sponsored convention instead of a civilian convention.
Check out DEF CON Security Conference @ www.defcon.org