This is bizarre. This piece insinuates, with not a shred of evidence, that Google+ identity data is linked to Google Analytics data, and there is zero evidence that this is the case, or that it even makes any sense. (For starters, Google Analytics tracking code never touches the google.com domain in any kind of way and thus couldn't be used to link to account information.)
http://googleblog.blogspot.se/2012/01/updating-our-privacy-p...