Who uses social networks know that own profile info and the contents posted (status, photos, etc…) are sensible data and the privacy is a very important topic.
Facebook offers various privacy options.
First of all you can set the visibility level for each info of own profile as well as the contents published. You can decide to set as public, friends only or private.
Every time you use an app/game connected to Facebook you are informed about what info the app/game want to access and you can decide to accept or not.
In Facebook privacy settings you can set who can see your stuff, who can contact you and who can look you up.
In Timeline and tagging there are settings about your timeline and tagging feature.
In Blocking section you can block someone, block invites from certain people, block invites to events from certain people, block applications and pages.