Re: Who would not do this?
"Surely nobody leaves their Bluetooth open like that?"
I think you have to explicitly enable it to discover something via bluetooth. And don't call me Shirley.
That being said, if you have BT headphones connected, and you pause, and then resume again (oh I'm on the train I want to make a phone call now), it probably re-connects your bluetooth stuff too on power up [which would make you vulnerable for that brief period of time].