Mode S transponder display to ATC?

Everett M. Greene wrote:

Taken to an extreme, it would seem that the
German equivalent of the FAA can't record ATC transmissions
and use them for quality control, training, or violation
proceedings since uninvolved third parties will have been
recorded.

No, it's not. ATC comms are recorded and that is public knowledge (at least
among those participating). You basically consent to being recorded by
transmitting.

Realize that privacy laws do not protect you against other people listening
in or recording what you are saying. They are however protecting you
against being listened to or recorded *without* *your* *knowledge*.

Michael Huber writes:

Realize that privacy laws do not protect you against other people listening
in or recording what you are saying. They are however protecting you
against being listened to or recorded *without* *your* *knowledge*.

How are you able to determine who is listening to you when you talk to ATC?