They conflate the public sphere with the making of a public. That is, when I blog something, I am publishing it to the world for anyone and everyone to see: the more the better, is the assumption. But when I put something on Facebook my assumption had been that I was sharing it just with the public I created and control there. That public is private. Therein lies the confusion. Making that public public is what disturbs people. It robs them of their sense of control—and their actual control—of what they were sharing and with whom (no matter how many preferences we can set). On top of that, collecting our actions elsewhere on the net—our browsing and our likes—and making that public, too, through Facebook, disturbed people even more.
via buzzmachine.com