>c) On Reddit and like sites we see behaviour that we would never tolerate if we saw it in real life. Why do we not only tolerate it online, but suddenly elevate such antisocial behaviour of the extremest kind to a mystical status of "expression of free speech"? There is a reason we are taught "manners" as children: without a minimum of politeness, societies cannot function. Politeness and courtesy have to do with respecting another's person even if you don't share his (or her) opinions, with tolerating people who are different from you. And is that not the very epitome of freedom?

Because internet communities regularly raid each-other. Someone who's a dick to you on reddit may just be a troll from 4chan with a new-made alt-account. Community and politeness require a relatively fixed set of identities with which to interact.