Bluetooth issues

E0 stream cipher (128bits key) has known weakness (classical divide-and-conquer method),
PIN code usage for the initialization process is unstable, (ad-hoc management)
The truth of the Init Key is quite low (think of 0000 PIN Code),
The link key process can be used to gain access to other device,
The Bluetooth Device Address is unique and tracing behavior is possible (privacy issue),