When I worked at McDonald’s I used to keep the DriveThru headset on after closing while I was doing paper work to tell people “sorry, we’re closed” if they drove up to the speaker board. (Mind you, the building lights and menu board lights are off at this point. Something we call a “clue”.)
That stopped after one too many people screamed “FUCK YOU!” into the speaker board (for us following our posted hours and me politely informing them instead of ignoring them.)
You quickly adopt a policy of “just ignore them and they’ll figure it out.”