We want to bring additional users into our Chatter with Chatter Free licenses, but realized that some sensitive posts have been made outside of bespoke private groups. This is causing a problem since we don't want the new users to see those posts. I can't solve this with Visualforce and Chatter does not support blocking users.
Short of deleting dozens of posts, are there any ways around this? Can posts and their comments be moved into private groups after the fact?
A quick test in the Developer Console shows that you cannot UPDATE FeedItem so these posts cannot be re-parented.