Google is not just an industry itself it's also an experimental machine.. Below you will find another beta from google's experiments.
I'm not trying to broadcast Google breaking news.. It's a feature that have been launched a year before.
So what's the case?
Doing a simple Google search when you're signed in with your gmail account, in the SERP you get some results taken from your "social circle" another Google feature. So for my query "πες μου" for a facebook page i also got a result from one of my connections which means that when you are signed in, Google algorithm except Page Rank* is filtering the results according to your Social Circle.
What is coming next? Social Rank?
Try it and find out your connections and the paths that you are connected. Day by day, we are getting more and more tightly connected. And this is not a trend, it's a philosophy and it's here to stay..
*PageRank is a Google’s trademark and measures the importance of each page on the internet This rank depends on the number of the incoming links of the page, the number of links per page and the quality of links that point to each site. source WebSeoAnalytics