Barnaby Jack, the security researcher who demonstrated cash machine hacks live on stage in Las Vegas and later highlighted the insecurity of smart medical devices, has died. His passing comes days before the opening of the Black Hat hacking convention in Vegas, where he was due to give a talk on electronic medical implants for humans. Barnaby Jack, a celebrated computer hacker who could force a bank ATM to spit out cash and sparked safety improvements in medical devices, has died in San Francisco on Thursday, aged 36. He once said he could kill a man from 30 feet away. His genius was finding bugs in the tiny computers embedded in equipment such as medical devices and banking machines. He received standing ovations at hacking conventions for his creativity and showmanship. He became one of the most famous hackers on the planet after a 2010 demonstration of "Jackpotting" - getting ATMs to spew out bills. More recently, he emerged as a leading expert in the weaknesses that could be found in medical technology. He discovered flaws in widely-used insulin pumps which allowed him to compromise the devices. The hack made it possible to control them and administer a fatal level of insulin, Mr Jack said. "My purpose was not to allow anyone to be harmed by this because it is not easy to reproduce," "But hopefully it will promote some change in these companies and get some meaningful security in these devices." Mr Jack's expertise and vivid demonstrations of his knowledge at events like Black Hat earned him the respect of many security professionals. Some people believe that... He was a researcher. He investigated these vulnerabilities so he could inform vendors how to make their products safer or more secure. He did not exploit these vulnerabilities himself for personal gain. He was unquestionably one of the "good guys." Some people disagree. What is your opinion? BHW members?