Bluesnarfing is one of most famous of all bluetooth attack on devices.
It is a major security issue since the advent of bletooth technology and is often thought to be in the same genre as ""hacking"
It was thought to be first discovered in late 2003.
Technical details aside. When a person performs a bluetooth attack, he is able to connect to another persons bluetooth devices and able to gain access to the files on his device. This means that he can read all the messages, files and even photos on the victims device.
Not surprisingly, bluesnarfing is not legal.
This is sometimes confused with bluejacking in which users can send anomynous messages to the victims devices, which is esentially harmless.
Hope this helps.
Will post more about the technicalities of it next time.