Well, Google and FB searches and messages respectively contain many personal secrets, so I understand having concerns about where that data is going and who might have access (although I am told the data controls are very strict).

But I do a similar question to you. Why is it that people are worried about their Google and Facebook data as opposed to the data at their health insurer or at their bank or their local government? That data is far less secure, the data security policies (if they exist) are relatively trivial. For business purposes, what a bank or health insurer might do in pursuit of money would screw up your life more than Google or FB trying to sell you stuff. Local government could certainly cost you far more money or get you into more legal trouble.