I know I'm resurrecting an old discussion that some of you may consider resolved...
But from the perspective of someone relatively new here, groups privacy is confusing and uncontrollable. I assume that what I'm writing now will be indexed by Google because I tried Googling a snippet of another group discussion and it appeared in the search results. Maybe I'm wrong(??) - but as I write, there is nothing appearing on the web form that informs me who the audience of this post will be. When I look at all the preceding posts in this discussion, nothing tells me which of them are viewable by non-members/search engines etc, and nothing tells me whether or not this entire thread is members-only or freely indexable.
Like TimLoal, I think best practice is to allow each author of anything published on the site (starting with groups) the ability to have complete control over their audience, and for anyone with the credentials to view that content to see what the audience is.
When I post to a group, for example, I'd like to see a few clearly visible check boxes:
Choose the privacy level of this post:
[ ] 5. only me
[ ] 4. only members of this group
[ ] 3. only BW members (including those not a member of this group)
[ ] 2. any person (including non-BW members)
[ ] 1. all people and search engines
And when I start a new group discussion myself, I would like to have the same options to apply to the entire thread, including the subject heading / title (still allowing discussion participants to choose a higher privacy level for their individual posts, should they choose to do so).
The privacy level of each item published on BW would be clearly labelled and visible by all who have privileges to view it. Perhaps items that are hidden due to privacy could be replaced by a grey box, or some kind of indication of their absence.
The principle is one of choice and transparency. Privacy is, IMO, not a one-size-fits-all issue.
Maybe this is too difficult to implement? I'm not a web developer. But in my opinion, I would feel far more confident contributing to the community if I knew that I had such a level of control over my privacy.