Google is putting people's face icon's on it's advertisements. Anytime you hit a #1 or give a review for a Google product, even if you don't have a Google plus account, your face could be used in an ad.
They're doing this because it's a great sales ploy, after all, if you Google a product and you find Aunt Sally endorsed it, you'd be more apt to buy it wouldn't you? People on friend's list will appear to you before strangers do because it's a sure thing to grab your attention.
If you don't want your face to be on digital ads you need to go here and read through it and untoggle the checked box: plus.google.com/settings/endorsements?hl=en
I do have a comment for network marketers... wouldn't this be great IF YOU got a piece of the revenue? I'm not advertising for free. Unchecked the box.
As further precaution, you should NOT click the + or leave any Google related reviews.