In business, call recording is a must for a number of reasons, be it legal or ethical. However, since smartphone mobiles have made an appearance, call recording has taken a bit of a nosedive – after all, it’s a lot harder to record calls on a mobile – and tapping into calls on a mobile? Forget it. That kind of technology costs a bundle and is solely the realm of law enforcement and government agencies. Or is it?

Chris Paget, a technology security consultant, has developed a cheap and easy-to-build IMSI catcher – i.e. a device that allows you to tap into calls made on mobile phones and listen in to them – or record them. He’ll be showing fellow hackers how to build this device at the annual Defcon security conference in Las Vegas.