Enlarge / My DEF CON badge, complete with Wall of Sheep add-on. My puzzle quest is far from complete—it may require reprogramming and flipping a component. (credit: Sean Gallagher) Nearly 30,000 people came to Las Vegas last week for the 26th edition of DEF CON, the iconic security conference. And no small amount of the mental energy of that vast crowd was spent on one particular thing: the conference badge. This year's badges, designed by Tymkrs, were elevated works of printed circuit board art with a collection of LED-lit features, including red and green human figures and a color-shifting DEF CON logo.