And just because of that (i.e. making it available online) I cannot even begin to describe just how much good this might do in the world.

I could expand this sentiment to every teacher or lecturer who has chosen to put their video online, especially the great ones. They have done a great service to the world (probably beyond what they may themselves realize).

I recently met an undergrad student in India who considered Steve Huffman to be his guru (he was a fan of his Udacity course, and so am I, btw) and swears by everything Steve taught him. And, Steve probably does not even know that he has a fan following in a small town in India :)