Thanks for having a first look at this, Ray.
It might be helpful to break out the various ways in which the "private" request might be fleshed out:
1. I don't want anyone at all to know that I have a Commons account.
2. I want my Commons account to be totally anonymous.
3. I want my Commons account to be hidden from non-members and/or non-friends.
4. I don't want the Activity, Groups, etc tabs of my profile to be visible (to anyone, to non-friends, etc)
5. I don't want to have a Public Portfolio.
6. I don't want to appear in the Members directory or in search.
7. I don't want to appear in the member listing of groups where I'm a member.
All these are legitimate requests, and some of them are related to each other, but we would have a hard time building a system that accommodates them all equally. I think it would behoove us to sketch out priorities. For example, Ray's mockup (if implemented by itself) would address 4 and 5; we could also couple it with 6 for some sense of 'anonymous'. But it doesn't fully hide one's landing page. To do this we would need to have some redirect logic, and we'd also need to stop showing links throughout the Commons where the user name appears, and so forth. And there are certain kinds of "hiding" that probably aren't compatible with the way the Commons works - if you write content on a site, it's hard (and arguably a bad thing) to hide the byline; if we hide you from group membership rolls, it's hard for group admins to manage the group; etc.
