If you're concerned about your privacy, you should look at System Preferences > Spotlight > About Spotlight Suggestions and Privacy
The problem is that even after disabling it there, Spotlight still attempts to phone home. Here's a screenshot with "Spotlight Suggestions" and "Bing Web Searches" disabled in System Preferences with a Little Snitch window showing an attempted connection while searching: http://imgur.com/w09aNpz
The problem is that even after disabling it there, Spotlight still attempts to phone home. Here's a screenshot with "Spotlight Suggestions" and "Bing Web Searches" disabled in System Preferences with a Little Snitch window showing an attempted connection while searching: http://imgur.com/w09aNpz