Ah, defcon drama!
Old ones used to be much better anyway.
(“Had to” means a friend offered me one, laughed, and said “aw, c’mon”. I could’ve easily said no.)
First, I literally saw them do shots during a talk yesterday for some first-time presenters. Secondly that WASN'T the "old defcon" either! Drinking is a relatively new tradition in the history of the con. I've spoken twice. Once at DC 17 (no shot offered) and once at DC 23 (shots were offered). There's video proof:
No drinking, DC 17: https://www.youtube.com/watch?v=okPWY0FeUoU Asked to drink, opted for a coin instead (we were asked beforehand): https://youtu.be/6dmvtbrM6hs?feature=shared&t=1153