One of my professors told us about the time he did a request to Facebook to send him all his data. By law they had to send it on paper. They brought it in a big truck.

All the stuff he'd deleted was still there, just with "(deleted)" next to it.

They have a lot on people without Facebook accounts though, because their tracking stuff is all over the web.

I always found it weird that Instagram gives me much better ads than Google does... Google should know much better!