It seems like there are three big differences between how Google is handling this and how Facebook handled this:
- Google is blasting the notice pretty visibly all over the place. Open a tab and you can't help but see info about it. It is in your notifications. They are making it loud and clear that this is going to happen, and being pretty transparent about what it means.
- Google is making it easy to opt out. If you opted out of some things, or if you're in an apps domain, you're already opted out. If not, there are prominent links telling you how to opt out of this.
- This is only happening for public activities. You can argue if a +1 or a review should be public or if it violates Google's own concept of circles, but they're making it clear this won't apply to things you share privately.
I may have issues with how they're forcing some activities to be public only, but I can't fault them for trying to make it very clear what is public, what is private, and how they intend to respect the difference between the two.