How Bluetooth Surveillance Works

If you own a Bluetooth device, can someone trace your activity? See more ­bluetooth pic­tures.
Siri Stafford/Getty Images

­If you were to randomly pick up a piece of electronics equipment in your house, there's a reasonable chance that it has Bluetooth capabilities, especially if the gadget in question is fairly new. Whether it's a cell phone, smartphone, laptop, printer or keyboard, Bluetooth wireless technology has made life easier for those of us with too many electronics on our hands. Bluetooth devices get rid of frustrating wires and expensive adapters by using short-range radio signals to connect devices to each other and send information back and forth.

Bluetooth is especially common in mobile phones, which make up more than 60 percent of the Bluetooth market [source: Bialoglowy]. Bluetooth headsets, for example, transmit calls from your phone to the headset in your ear -- this allows you to keep your phone in your pocket, backpack or handbag while walking around. It's also helpful to drivers wanting to cruise around hands-free [source: Bajarin].

Imagine, though, talking a walk through a crowded area -- perhaps the shopping district of a big city. Maybe you're just doing some casual window shopping, and you've kept your phone with you and left Bluetooth on "discoverable" mode. This allows other Bluetooth phones to locate you. As you linger in front of a shoe store and consider a new pair, your phone beeps: Someone's sent you a text message. It reads: "We know where you are. Having fun shopping?" Sounds like something out of a movie, right?

Such a thing is possible, and it's happened before. In fact, it's the very nature of Bluetooth -- a technology that can search for and locate other devices that also have Bluetooth -- which has some people concerned. Security has long been an issue with this technology -- bluejacking, for instance, although simply a harmless prank, allows Bluetooth users to send out unsolicited messages to nearby devices. Because Bluetooth devices are to some degree traceable, the concept of Bluetooth surveillance has been introduced into the tech world.

The phrase Bluetooth surveillance might conjure up images of Big Brother in George Orwell's dystopian novel of the future, "1984," but is that really the idea? How does Bluetooth surveillance work, and who would use it? Can it be used for good or for evil? To learn about Bluetooth surveillance and whether or not you should remain discoverable, read on.