When I am logged into my Google account and I search anything on Google, these days if it is a blog or a profile, Google shows the name of the owner. and also tells me if I am connected to that person.
I can understand if Its a blogger blog where the author might be having a Google+ account which I am connected to.
But under my Facebook friends account in Google search results. It reads "You are connected to XYZ on Facebook" on hovering over is name.
Is it because I told Google Plus about my other profile links, ie Twitter and Facebook ?
I don't think connections are accessible under Graph API without any access token and I don't remember giving Google any such permissions.
The Google dashboard at https://www.google.com/dashboard list what Google knows about you, under the section "Me on the Web" I believe you can adjust what twitter/Facebook profiles are linked to you Google account. I don't have any so I'm not %100 sure but a good place to check.