Their stated goal is to "organize the world's information" but notice there's never a qualifier of the world's public information. While they've been able to d

Their stated goal is to "organize the world's information" but notice there's never a qualifier of the world's public information. While they've been able to determine a ton of information about social circles from interactions (gmail, voice, gchat, hangouts), the real understanding comes from G+ where we've categorized our contacts. Odds are you have circles that represent locations, employers, family, friends, clubs, etc. By analyzing those groupings, they can determine the relationships that aren't obvious just from the interactions. Now, combine that with the previous information and they know when you're talking with someone from HR from another company and how closely that company is linked to yours via shared/common circles. Sounds like a opportunity to sell an ad for 401k rollovers. :)