Parents' Weekend at MIT is an official time for the parents of freshmen to visit MIT and find out how their children are doing and living. There are scheduled events for both parents and freshmen to attend together; the 1991 events included Brian Leibowitz's hack talk.
All was quiet as the lights went out for the hack talk. Suddenly, there was a loud, booming rumble. A contingent of SPODSA commandos, dressed entirely in black, invaded 10-250 and grabbed an unsuspecting freshman. Two of the SPODSA commandos publicly read an arrest warrant detailing her nerdly crimes. She was then stuffed into a body bag and carried away. Finally, Brian was asked to sign the receipt for her, sign for his copy of the receipt, and for the commando's copy of Brian's copy of the receipt.
The entire hack seems to have been based on the abduction of Joe Buttle in the movie Brazil.