So the people who are unknowingly using G+... aren't really generating anything for Google to use, are they? They want to show your reviews alongside ads. Well,

So the people who are unknowingly using G+... aren't really generating anything for Google to use, are they? They want to show your reviews alongside ads. Well, if you're making reviews on Google+, that's not really "unknowing". If you're sharing, +1'ing, following, or starring content on G+, you're not really unknowingly using G+. So basically people who technically have a G+ account but never use it shouldn't be affected, because you have to use G+ to generate this content.