Your name. Your location. All your friends. Your family. Your work history. Your schooling. Your birthday. Your checkins. Your events. Your hometown. Your likes, photos. Your relationships. Your religion and politics.
And not just for you, but for one and a half billion other people.
While you’re at it, also read My Cow Game Extracted Your Facebook Data.
To be honest, I’m not even sure I know what the Facebook platform’s terms of service dictated that I do with user data acquired from Facebook. Technically, users could revoke certain app permissions later, and apps were supposed to remove any impacted data that they had stored. I doubt most apps did that, and I suspect users never knew–and still don’t know–that revoking access to an app they used eight years ago doesn’t do anything to reverse transmissions that took place years ago.
Insert pithy statement about closing the stable door after the horse has bolted here.