Is it only an emotional reaction, though?

When an algorithm sifts through my e-mail the result is that I see a more targeted ad.

When I mess up and inappropriately share something on Facebook it is obvious to lots of people in my life. (And, of course, Facebook tends to vomit up some sort of privacy outrage every five months, so there is always the nagging worry that something one did share in a reasonable way is now being seen in a way one didn't intend under the old "rules of the road".

While some people may care about privacy as an abstract first principle, I imagine many people are more concerned about the consequences of other people knowing something about them.