Setting Your Privacy Preferences
Although Facebook is open to the public, your life doesn’t need to be. Facebook provides privacy settings you can use to restrict or allow access to your information and activities on Facebook. By default, only your Facebook friends have access to most of your Profile information and can see your status updates and various activities you engage in.
In addition, Facebook never discloses pokes (except to the person you poke), messages (except to the recipient), whose Profile or photos you view, whose notes you read, groups and events you decline to join, friend requests you ignore or reject, friends you remove, or notes and photos you delete.