To have discussions with a set of people that is not otherwise public.
None. See group for where examples are likely to happen first.
Perspective and Itches
- Tantek Çelik I have found some use for private groups on Facebook and I have captured my thoughts about that and how I might try to start implementing them in my own software and on my own site here: Falcon#Private_Groups
Facebook has support for private groups of various levels, including "secret" where the very existence of the group is hidden from searches etc.
If you mention a non-member (via link) in a group-only post/message, Facebook will display a grey circle and slash icon next to the person's name, as well as showing their name in grey, to indicate that person was not notified of that reference, can't be notified because the reference is on a post that they do not have access to. E.g.:
The same thing happens in private events, which are essentially one-off private groups.