I think the whole "if it's free, you're the product" nugget of information has not been broadly understood by folks, or if it has, maybe folks don't care as much about their data.
I do live these days with the understanding that pretty much all of my personal info is out there one way or another, a social security number is about as private as a phone number these days.
freedomben
I think people genuinely don't realize how invasive the data gathered is. If they knew what engineers and admins can see, they'd be floored
captainkrtekOP
Totally, I think there are lots of assumptions of its just the data they explicitly put into the system, eg: "likes", "comments", "photos", but not the darker side of correlating activity across sites, interests, building profiles of you, selling your history, etc.
I do live these days with the understanding that pretty much all of my personal info is out there one way or another, a social security number is about as private as a phone number these days.