The one which was tapping phone calls was completely separated from the one which controlled the letters, for good reasons, because if one agent quit the Stasi, his knowledge was very small.
전화를 도청하는 부서는 편지를 관리하는 부서와 완전히 분리되었습니다. 타당한 이유가 있어요. 요원들이 슈타지를 그만둘때 개인의 지식을 최소화 하기 위해서죠.