While we were at the same organization, there was a lot of insider new that would come my way as well that of M. However, though we were both flatmates, met everyday and shared almost every story of our lives including, of course, talking of office, but we never divulged professional news or secrets to each other. Even the basic information requirement was via official mails, and not over a phone conversation - just like i would behave with another colleague. News of impending possible acquisitions would not be known by her (or to other frnds of mine who wanted to know if share prices could rise) and potential gossip would not find its way to me.
And, it was perfectly acceptable to both of us, and infact, I liked her for that, and Im guessing she me. It was (and is) considered basic business ethical behavior. The company divulges in you presuming your confidentiality on certain counts. That it will be open news tomorrow is a matter of tomorrow.
Yes, it was assumed by most initially that I would know stuff because we stayed together, but soon they knew better. And that helped in both our professional lives.
I mean, I would get news of changes in policy, resignations, recruitments, timelines and basic HR procedures only via usual channels, and not through her. Of course, if I had a whiff of info I could go ahead and ask and she would tell me, but we needed to know what to ask.
And all this even when we both knew how secretive we could be. That news never passes our lips till its out in the open.
This helped me cultivate a sphere of ppl who would give me vital information, rather, tune into the grapevine. A very useful habit for myself. To continue in future.
Hence, I do not understand the urge of people who want to tell all to their friends. Sure, trust is good and it all depends on people, and they will not tell anyone. However, news given in confidence should remain that way. Especially when you are responsible for keeping it that way.