According to a Google+ post from Google+ team member Wen-Ai Yu, “We’re working on expanding this to more folks.” As you can see in the video, she doesn’t describe exactly how these verifications work.
The program, along with Google‘s insistence that user accounts be opened under a real name, aims to assure people that “the person you’re adding to a circle is really who they claim to be.”
Google’s Wen-Ai Yu explains:
