Me too! I find that I have gained a lot of confidence from chatting online (a bit like your point on the other thread, about noting points before you get a chance to say them, but noting them does something useful for you).
(So thank you for that! I luffs you all)
I think to people who are privileged by their persona in "real life" encounters, this online stuff feels like "barbarians at the gate". It is the very fact that anyone can speak which is so threatening, as they have internalised a confidence in life's "quality control" measures, in self-justification, when they not controlling quality at all - controlling all sorts of other stuff, but not quality.
In fact quality control is very easy online. You can read and sort through stuff very quickly that in a real life conversation you would be forced to put up with, through politeness, for ages.
Not being in academia, I am interested to learn that so much importance is attached to bums on seats. When I was at college no one cared what I turned up to. It was my education, and I was free to piss it up the wall if I wanted - but the exams would take no prisoners. If checking continuing engagement is now important, there are brilliant online ways of doing this effortlessly - a 5 minute IM "mini-viva" taking place at certain points throughout the term could allow a teacher to say "great stuff, carry on doing what you're doing" or "seriously? that was a trick question, there was no 4th Silesian War. Pull your finger out"