隔墙有耳

Explanation: Separated by a wall, it was overheard. Even if the secret to discuss metaphor, others may know. Also used to persuade people to speak carefully, so that leakage. 　　Usage: Contraction type; as object clause; that care secrets leak 　　Source: Guan Zhong "pipe under the monarch and his subjects": "Walls have ears, V Kou in the side. Walls have ears who seek micro-leakage that also." 　　Examples: Unexpectedly friends and talk, forget the ~, all coming down the Yang Qu ears. (Qing Zeng Pu, "Flower," the thirty-third back)