Google is making it easier to hide the searches you want to keep secret
Perform a search using Google, and details of your search are saved in your Google account for posterity -- unless, of course, you take action.
If you want to keep a search to yourself, you could use Incognito mode in Chrome and it will not be saved. Or you could manually delete your search history, although this does mean losing potentially useful historic information; the same is true of the auto-delete option for your online activity. But now there is new option to delete the last 15 minutes of search activity -- just enough to cover your tracks when you need to.