Google is now "personalizing" results even when users have not logged into its web-dominating search site. And SEO types aren't too happy about it.
Personalization is a euphemism for a Google-controlled practice that involves tweaking your search results according to your past web history. Mountain View was already doing this with users who had signed in to a Google account so they could use non-search services like Gmail and Google Calendar. But now it's targeting results for all users - whether they're logged in or not.