Well, besides the phone book and disclosure of some fairly sensitive information, they can make calls, review your caller ID list of call you received, and a list of calls you made. With external antenna on the hostile device, Bluetooth has a range of up to 3300 feet. Still not much of an issue on your phone, but there ar other bluetooth devices (computers). Once they get into the phone, perhaps the interface would allow other opportunities for mischief in the GPS or Emergency Assist functions.