The hacker's phone buzzes as he approaches the police station."One, two, three …," he counts the notifications.Each one is another police officer detected; his screen details their exact coordinates."… Seven, eight, nine, 10."This isn't hi-tech spy craft; it's an app available on app stores.Bluetooth-enabled tasers and body-worn cameras, used by thousands of Australian police officers, can inadvertently reveal their real-time location to any criminal with a phone or laptop.Police services around the country have been warned of the security flaw Most mobiles, like Apple iPhones, have built-in privacy features that randomise the code and make them harder to track.This hacker realised US tech giant Axon, which sells tasers and body-worn cameras to police around the world, had failed to do the same."I was just logging Bluetooth devices on my phone … and started seeing body-worn cameras and tasers appear in the logs and [thought] that's a bit odd."I think it comes down to either incompetence or laziness … it just seems like the engineers who developed this were either ignorant or incompetent," he said.The man, who doesn't want to be named, showed Four Corners how he built his own proof-of-concept software, and was able to locate and track officers by the fixed, public MAC address assigned to any Axon bluetooth-enabled device."You can track police devices … from quite a significant distance away," he said."It'll just give it a little alert … saying 'police detected'."Tonight on Four Corners: The tactics of the multi-billion-dollar tech giant behind tasers