[rolandog]

Right, but isn't it noisy ... at the headphone level? (i.e. not heard when not wearing them?).

What I'm getting at is that I think the risk varies depending on how often you leave the headset paired; for example, if the headphones are over-ear, those are more prone to not be turned off --- and remain connected; thus, a greater chance of success for establishing a BlueTooth classic connection without getting noticed and performing the WhatsApp account take-over until they listen to "I'm gonna take a shower, honey!" in the distance.