Former US vice-president Dick Cheney has revealed that his heart implant was altered to prevent terrorists from hacking into it.
Mr Cheney, who was former president George W Bush's right-hand man in the "war on terror," has had a long history of heart troubles.
Prior to his heart transplant nearly two years ago, Mr Cheney underwent a series of life-saving procedures, including an implanted defibrillator.
But his doctor, cardiologist Jonathan Reiner, had the device's wireless function disabled when it was replaced in 2007 so that terrorists could not trigger a fatal shock to his heart.
"I was aware of the danger... that existed... I found it credible," Mr Cheney told CBS television.
The danger was publicly disclosed in July by a New Zealand computer hacker, Barnaby Jack, a celebrated computer hacker who died in San Francisco, a week before he was due to make a high-profile presentation on the problem at a hacking conference.
Mr Jack, 35, was found dead in San Francisco, where he was one of the world's most prominent "white hat" hackers - those who use their technical skills to find security holes before criminals can exploit them.
Mr Jack had planned to demonstrate his techniques to hack into pacemakers and implanted defibrillators at the Black Hat hackers convention in Las Vegas, and had told Reuters that he could kill a man from nine metres away by attacking an implanted heart device.
Mr Jack turned his attention to medical devices, while working on a team at McAfee that engineered methods for attacking insulin pumps. Their research prompted medical device maker Medtronic Inc to revamp the way it designed its products.
The US government also noticed Mr Jack's work.
"The work that Barnaby Jack and others have done to highlight some of these vulnerabilities has contributed importantly to progress in the field," said William Maisel, deputy director for science at the Food and Drug Administration's Center for Devices and Radiological Health.