The Hacker Who Poked Holes in Medical Devices

Barnaby Jack, the 36-year-old hacker with a showman's flair whose death was reported last week, set an ambitious goal a few years back: Help secure the millions of insulin pumps, pacemakers and other medical devices implanted in people around the world.

Hackers are often thought of as troublemakers and criminals, and indeed, many are, as shown in the indictment last week of five people in the theft of 160 million credit card numbers. But for security professionals such as Jack, who are paid to find and fix vulnerabilities, hacking is about helping, not hurting.