The Bluetooth wireless protocol has made it easy to zap data from your desktop to your PDA without the device ever leaving your belt. (Bluetooth is also responsible for the futuristic, cyborg-like, wireless cell-phone accessories adorning more and more people's ears.) However, due to the way manufacturers are implementing the Bluetooth protocol stack, bluesnarfing and bluejacking (ways to steal people's address books and personal information stored on Bluetooth-enabled PDAs) are a real hazard. Although the conventional wisdom has been that Bluetooth's relatively short range limits this danger, recent research has shown that Bluetooth devices can be accessed from as much as a mile away with the right combination of directional antennae and software (see Wirednews.com, "Security Cavities Ail Bluetooth," August 2004, for more information). Another exploit called Bluebug lets anyone call a Bluetooth-enabled phone and secretly listen in on the user's conversations.
With most Bluetooth-enabled phones, the Bluetooth discoverable mode (this mode may be named differently on your phone) is turned on to enable easy Bluetooth bonding with other cell phones. However, when the Bluetooth discoverable mode is on, most exploits can easily access your phone. To protect yourself, if you have a Bluetooth-enabled phone, make sure the Bluetooth discoverable mode is turned off (refer to the manual you received with your phone for instructions).