I understand that... but it all seems a little far-fetched. Bluetooth devices have to be paired with each other to really do anything that could be considered serious. In other words, even you manage to hijack my pairing information from my phone to my car using a hostile device, it does not mean the hostile device will work with my PC -- that is assuming, of course, that you'd even KNOW where my PC is... or that I even use BT to communicate between my phone and my PC.
For the most part, Bluetooth is being used to pair phones with cars, phones with headphones, and phones with PCs (to transfer adressbooks). If you consider my mom's telephone number "sensitive" information, then yeah... otherwise, we may be making a mountain out of a molehill.
Wanna talk about security breaches? Download PC (or Mac) Stumbler, turn it on, and go driving around your neighborhood with your laptop on. Tell me how many wi-fi networks named "Linsys" you'll see... and ALL of them UNSECURED! Now, THAT'S dangerous.
Juan