Facebook has been selling information to government agencies and giving clandestine access to information security firms.
Some of these so-called whitehat infosec firms are working for authoritarian governments, such as those of Egypt and Syria.
Everything you do on Facebook stays on Facebook regardless of your "privacy" settings, and deleting your account is impossible, even if you "delete" your account, all your personal info stays on Facebook and can be recovered at any time.
It is building a virtual "condition" of that which has limits. Limits that will impose your physical, mental, and emotional states.
Changing the privacy settings to make your Facebook account more "private" is also a delusion.
Facebook knows more about you than your family. Look at the mess we've made. Time to wake up.