One such droid was used by Darth Vader in his interrogation of Princess Leia Organa in 0 BBY . When Leia Organa underwent her mind probe, she was injected with a powerful mind-altering hallucinogen that made her very susceptible to suggestion. With mere words from Darth Vader, Leia imagined herself in unbearable pain, though she was not undergoing any physical harm whatsoever. Her uncanny fortitude prevented her from divulging any Alliance secrets during this torment. IT-O models also did guard duty within Detention Block AA-23 , with Luke Skywalker encountering such a model while trying to rescue Leia.