Google+ is being tweaked to move it in an even more.
Google said today that it was completely eliminating the ability to share certain semiprivate posts more widely. That option was previously available as an option for users.
At the moment, if I created a post and specified that it could be viewed only by family members, they would nevertheless have the option to share it publicly--the Google+ equivalent of forwarding e-mail--unless I remembered to select the "Disable reshare" option.
Google engineer Kelly Ellis said in a video that: "Starting next week, limited posts will not be sharable publicly--this is really important to us. On Google+, you should be in control of who sees your posts."
Even at the time of itsearlier this week, Google+ prevented users from sharing the entire thread of a limited discussion. Now (unless they copy and paste) they can't share the initial post either.
Ellis also said that Google was improving the way posts are displayed to avoid flooding users with a deluge of updates.