Walls have ears 英文諺語
Walls have ears 壁上有耳
Said as a warning that you think your conversation is being overheard, as it emphasizes that someone may be listening.
This phrase was used on many propaganda posters during World War II. It was basically a reminder to civilians involved in the war effort to be wary about what they spoke about, or to whom, for fear of information getting into the hands of enemy spies.
The conversation is easily overheard, someone is listening, as in Be careful what you say; the walls have ears. This saying may come from a story about Dionysius of Syracuse (430–367 b.c.), who had an ear-shaped cave cut and connected between the rooms of his palace so that he could hear what was being said from another room. Similar listening posts were installed in other palaces over the centuries, including the Louvre in Paris. In English the phrase was first recorded in its present form in 1620.
“I Don’t say anything about our company sales plan here. Walls have ears.”