Admittedly, the headline is designed to get your dander up. You're in no immediate danger of a technologically-gifted thief plugging a couple of wires into your hotel door and making off with your sack of souvenirs from the Mall of America. But that's not to say it's impossible. Cody Brocious, who was recently brought on by Mozilla to work on Boot to Gecko, is giving a presentation at the annual Black Hat conference in Vegas where he demonstrates a method for cracking open keycard locks with a homemade $50 device. The hack only works on locks made by Onity at the moment, and real life testing with a reporter from Forbes only succeeded in opening one of three hotel doors. Still, with between four and five million Onity locks installed across the country (according to the company), that is a lot of vulnerable rooms. The attack is possible thanks to a DC jack on the underside of the lock that's used to reprogram the doors. This provides direct access to the lock's memory, which is also home to the numeric key required to release the latch -- a key that is protected by what Brocious described as "weak encryption." Ultimately the source code and design for the Arduino-based unlocker will be published online alongside a research paper explaining how these locks work and why they're inherently insecure. The hope is that manufacturers will take notice and improve the security of their wares before the world's ne'er-do-wells perfect Brocious' technique.