The 35yr.old ex-Aucklander was one of the 'good guys', making a career revealing the dangers posed by unscrupulous hackers combined with computer manufacturers' failures to install proper safety devices on equipment.
Jack thought it highly plausible that a terrorist could hack someone's pacemaker and speed up their heartbeat until it killed them! And he knew what he was talking about, having shown how to make cash machines dispense money by hacking into a bank's computers. He could also hack a diabetic's insulin pump from 10m away, so it would dispense a fatal dose...
Hmmm. You doubt it? He was due to demonstrate his work at a major computer-hacking convention in Las Vegas, showing how, with a wireless transmitter, he could trigger a power surge in someone's heart pacemaker and kill them from up to 20m away. However, a week beforehand, Jack was found dead in his flat in San Francisco. To say his sudden death is mysterious is putting it mildly.
Predictably, for someone working in the shadows, there've been many theories about how he died, fuelled by the coroner's refusal to discuss the case (other than to say that the autopsy results may not be available for possibly months). A local police source admitted this silence was puzzling. Jack's former work colleagues know of no medical condition that could have killed him.
"Sometimes you have to demonstrate the darker side," Barnaby Jack liked to say, as he justified his hacking skills. Has he become the victim of that 'darker side'?