DEFCON (also Def Con) is one of the largest events for hackers worldwide. In 2007, the conference had about 6000 visitors. It takes place annually since 1993 in Las Vegas, Nevada, instead. Within three days, it is reported about news in computer security. The course consists of lectures, workshops and meeting different people. As a rule, competitions are held. The most popular one is Capture the Flag (CTF ). The aim here is to defend specially constructed computers or networks or to conquer. Founded as the DEFCON by Jeff Moss - aka The Dark Tangent - which also Black Hat Briefings founded.

Meanwhile, there are many international DEFCON groups who pass on the knowledge in their countries and promote new ideas.


In 2001, the Russian programmer Dmitry Vitalyevich Skljarow was arrested at the conference. Adobe accused him of distributing software that can decrypt Adobe's eBook format.

The reporter Michelle Madigan was in 2007 accused of filming without a press pass or to make audio recordings.

In 2009, one person was arrested for possession of illegal firearms in Las Vegas. Another person cracked the door lock hotels on the roof of the Riviera and was arrested shortly thereafter.

In consequence of the PRISM revealed the presence of government employees to DEF CON was in 2013 for the first time not desired.