Bluesnarfing allows hackers to gain access to data stored on a Bluetooth enabled phone using Bluetooth wireless technology without alerting the phone’s user of the connection made to the device.
The information that can be accessed in this manner includes the phonebook and associated images, calendar, and IMEI (International Mobile Equipment Identity). By setting the device in non-discoverable, it becomes significantly more difficult to find and attack the device.
Without specialized equipment the hacker must be within a 10 meter range of the device while running a device with specialized software. Only specific older Bluetooth enabled phones are susceptible to bluesnarfing.