From Jim Edwards in Business Insider (still difficult to take this digital rag seriously because of their blatant disregard for Fair Use, copyrights, and inability to publish an article devoid of hypocrisy or common sense) with a few choice quotes on how Apple employees keep company secrets.
I couldn’t tell my wife anything; she knew I was working in a different building across the street and pulling very late nights, but she didn’t know what I was doing. When I had to travel to Manchester UK to work with more of the Transitive folks, she asked to come along. I had to say “no way” – she worked for IBM at the time.
Even within the company the culture manifests itself in interesting ways. If you have friends in other groups, they will never ask you what you are working on. They know better, and the courtesy is reciprocated. So usually conversations are personal, or about outside elements, or someone registering complaints about how the shipping version of your product works now (wink wink).
Big Brother is watching.