Hacker Matthew Jakubowski has posted a video (below) on YouTube that shows how anyone can build a pocket-sized device, 'James Bond's Dry Erase Marker,' which will open the lock on an estimated 4 million hotel rooms.
Jakubowski, a security researcher, told Forbes: "I guess we wanted to show that this sort of attack can happen with a very small concealable device. Someone using this could be searched and even then it wouldn't be obvious that this isn't just a pen."
The dry erase marker exploits a vulnerability in Onity locks, an inexpensive lock used on millions of hotel room doors, reports the Daily Mail.
Jakubowski's refined dry ease marker can pop most locks in a fraction of a second.