Stop apps and websites from harvesting your Facebook profile information
The best way to secure your Facebook information is to stop apps and third parties from gaining access to your profile, friends and timeline. This does mean you will not be able to log into websites using your Facebook account, play Facebook games, or like and share content via the Facebook social plugins that are installed on many websites.
Go to Settings Menu > Apps. Click Edit (under Apps, Websites and Games), then click Turn Off.
Of course, instead of turning off this convenience feature fully, you can review and limit which websites and apps have access to your Facebook profile.
The next best level of privacy on Facebook
Click on the little pencil icon to change the privacy setting for each individual app or website.
Select the checkboxes next to the websites and apps you want to get rid of, then click the blue Remove button at the top of the list.
Your posts and activity may still be visible if others are using older Facebook apps (which don’t have so many privacy settings).
Under Old Versions of Facebook for Mobile, select Friends or Only me from the drop down list.
Here are some other ways you can protect your privacy when using social media.