I say feedback because I'm usually acutely aware that we all think and work in circles, and the straight lines many of us think we see are merely a level of abstraction. I agree entirely with you about online/telephonic relationships - so does Monsieur Baudrillard, with his idea of the hyperreal, that hard seductive minimalistic glossiness that lures you in, trying and trying to get a rise out of it.

Re the echo chamber effect in your last paragraph, yes, definitely - and partly also because it's harder to tell immediately that someone is of this type. (I mostly just classify geeks as a subset of this class with a high degree of ability in non-social areas.)