The FSF has a lot of good material to read on why we don't want centralized control of our data. Applies to Facebook, Google, etc. As a card carrying FSF member (and supporter of EFF, ACLU, Software Conservancy) it embarrases me a little that I probably spend 30 minutes a day using Facebook, Google +, and Twitter; but I enjoy them, I keep the material I produce largely on my own infrastructure, and I work to prevent…
I don't see why you should be embarrassed to use Facebook et cetera. As I've discovered to my personal cost, there can easily be very real social consequences for opting out of these services, Facebook especially. I think you'd have to be Richard Stallman to blame someone for choosing not to suffer those consequences over a point of principle. And I don't think very highly of him for so doing, given the nomadic and largely asocial sort of life he's chosen. That such a life suits him is clear, and he's welcome to it, of course. But his judgment of those who find it not so easy to make the same choice is harshly contemptuous and utterly lacking in nuance, and I find that impossible to respect.