Jaron Lanier just published a book called "You Are Not A Gadget,"
I can honestly say that I know every single person on my FaceBook in person. Most of them, I see in person at least a couple of times a year. I have not added anyone to my FaceBook that I don't know face-to-face. That I will likely never have hundreds or thousands of people in my "Friends" List doesn't bother me at all. The people I have added are all people with whom I have some sort of relationship, something I couldn't say of other networking programs, like LJ, DreamWidth, WordPress, or Vox.
On those blogging sites, there are a lot of people I've never met face-to-face. I may never meet them in person. Because I had (and still have) an extensive correspondence list of colleagues and associates who aren't connected to the internet, most of whom I have also never met in person, this doesn't bother me. I perceive blog interaction to be similar to the interaction I get with my written correspondence and professional peers, just of a more random, and sometimes more personal, nature.
I don't know how others perceive things, but I am always acutely aware that other bloggers, commenters, forum members, and emailing list members are people, not ficitonal characters on some TV show or a computer program mimicking sentience.
Perhaps I don't always produce a sympathetic-sounding comment or post, and perhaps I read more than I comment, but never once have I ever forgotten that real flesh and blood people make those posts and comments. I am careful not to deliberately hurt the people I've added to my reading list even if I will most likely never meet most of them in person. That doesn't mean I never hurt or upset them, only that I don't try to cause hurt.
I am rather short with people I perceive as treating me or others in my comments as fictional characters or computer programs, who deliberately bait others or post anatagonistically, but I've been very lucky that few of the people who choose to comment on any of my posts at any of my blogs misbehaves in so trollish a fashion. I would like to believe it's because I know you are not a gadget or widget or program or made-up creation.
I know a living heart beats behind each post or comment.