If you've upgraded to Mac OS X Yosemite (10.10) and you're using the default settings, each time you start typing in Spotlight (to open an application or search for a file on your computer), your local search terms and location are sent to Apple and third parties (including Microsoft).
“Once Yosemite is installed, users searching for files – even on their own hard drives -- have their locations, unique user IDs and search terms automatically sent to the company, keystroke by keystroke.”
To fix this either follow the link to download their python script or follow the steps:
- Disable "Spotlight Suggestions" and "Bing Web Searches" in System Preferences > Spotlight > Search Results.
- You'll also need to uncheck "Include Spotlight Suggestions" in Safari > Preferences > Search. Safari also has a "Spotlight Suggestions" setting that is separate from Spotlight's settings.