Here's a very interesting Bluetooth experience.
I was driving by on the Highway and my phone which is connected to my car Bluetooth went off.
What happened next, just amazes me, someone changed the user ID on the Bluetooth and cloned my id to the car Bluetooth like nothing happened. Even though nothing was compromised a threat is still present. Anyone with the right tools can easily tap into your Bluetooth device and clone your phone, copy your personal contacts, retrieve personal information stored on your phone and if you have bank applications, even steal you banking passwords.
Bluetooth has no guard against these threats yet and it could be sometime before you ever do see this. So if you don't use your Bluetooth device on your phone, just turn it off until you need it.
see also:
Popular BlueTooth Hacks
Protect Yourself