Former US Vice President Dick Cheney has for years warned that America needs to be on guard against terrorist threats. As it turns out, he took that warning to heart quite literally. In a recent interview with medical journalist Sanjay Gupta on CBS News's 60 Minutes, Cheney and one of his doctor's revealed for the first time that the Vice President's pacemaker had its wireless feature disabled in 2007, "fearing a terrorist could assassinate the vice president by sending a signal to the device," as CBS News put it.

Pacemaker hacking has been demonstrated before in real life, notably by the late hacker Barnaby Jack. Cheney's cardiologist, Jonathan Reiner, elaborated on the risks to 60 Minutes, saying: "It seemed to me to be a bad idea for the vice president to have a device that maybe somebody on a rope line or in the next hotel room or downstairs might be able to get into — hack into. And I worried that someone could kill [Vice President Cheney]."

"I found it credible."

Cheney himself acknowledged that five years later, in 2012, an episode of the Showtime drama Homeland featured a similar situation involving a pacemaker used in a fictional assassination plot. "I found it credible," Cheney said of the episode. "Because I know from the experience we had and the necessity for adjusting my own device that it was an accurate portrayal of what was possible."

Cheney, a reformed smoker, has struggled with heart troubles for most of his adult life, suffering the first of five heart attacks in 1978 when he was just 37 years old. He had a heart transplant last year at age 71. He and Reiner have collaborated on a new book about his medical issues, Heart: An American Medical Odyssey, which comes out tomorrow.