let me re-phrase that for you
Obscenely wealthy owner» "the vast majority of the data that Facebook knows is because you chose to share it."
Well, let me re-phrase that: the vast majority of the data that Facebook knows is because you didn't choose not to share it.
In other words, we relied upon and took advantage of the fact that you have no idea how important your privacy is to you and we milked it for all it was worth. I am now worth billions of dollars. It was very decent of you to sacrifice your data in that way.