A famous example of this is Bletchley Park (an allied forces Second World War codebreaking centre where messages encrypted by the Enigma machine were decrypted) where people working in one hut would not know what the people in any other hut did.
A notable illustration of this is Bletchley Park (a wartime codebreaking center operated by allied forces during World War II where messages encrypted using the Enigma machine were deciphered).  Here, individuals working in one hut had no awareness of what their colleagues in other huts were doing.