In iOS 8 you can now quickly access your contacts via the App Switcher by double clicking the Home Button. If you don't want to look at a list of your favorite and most recent contacts every time you use the App Switcher, or if you don't want anyone else to easily see who you call or text most often, you can disable the feature in settings.
Go to Settings > Mail, Contacts, Calendars and scroll down to Contacts. Tap on Show in App Switcher and toggle Phone Favorites and Recents off. Your contacts will no longer appear in the App Switcher window.
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