Your house. Your family and kids. Your health status & insurances. Your job & income. Your car. Your friends. I'm guessing all of those things are, to a varying degree, important to most of us. We care about them, and that they are safe and well. We usually do not share too many details about them with complete strangers. Except when you use web sites online...

If you have wondered why you should cut down usage of the big company services such as Facebook, Google, Microsoft, Apple etc you should probably watch the movie The Great Hack.