Do you expect me to say that's a bad idea? We must have some serious cultural differences because as far as I am concerned, ignoring it and minding your own business are the only reasonable actions in such a situation. How can you possibly live your life confronting every stranger you find objectionable?

If for you privacy only exists when invading it is physically impossible, then can you really say that you have a concept of "respecting one's privacy" at all? It would be more accurate to say that you "respect the acoustical properties of walls".

There's a vast difference between asking people to consider the other people within earshot, and publicly shaming them.