We can't see the person before us, so we don't feel the imminent shared responsibility of the interaction. We only have words and we are only certain of our own emotions. In a way there's too much room for our imagination as well as less immediate responsibility, and we tend to project a lot when we don't have the experience of another person actually being there. The other person is replaced by our projection of them or by some otherwise weak perception of their motivations, and when we are putting ourselves against some opposing motivation, we get defensive and aggressive with all the comfort of holding on to our grudge safely behind our internet, and with none of the restraint by compassion and maturity.
And if we get to the point where we are offended - which is often just our perception and nothing else - we tend to hold on to that. We hold on to it like it's some treasure, and we listen to its demands and everything turns into some weird game of power, control and humiliation. All of this easily shows us where we are lacking in love, patience, wisdom and all other good things. And I'm not saying this as if I'm better than you, because I have to slap myself out of that mindset often. I find myself often feeling very passive-aggressive and snarky. But luckily I don't have to follow the demands of those feelings, I can just wake myself up, let it be and carry on with my day.
One of the funniest things about the kind of game where we try to one-up each other with snark and passive aggression, is the realization we get when we "lose" that stupid game. When I lose that game (which I shouldn't have participated in the first place), I'm thinking it would have been better if he just said "F you". There's some truth to that, I think. Just a plain old insult is more honest and less annoying than trying to find the "smart" way of putting someone down while I'm trying to raise myself into whatever useless imaginary and holier-than-thou pedestal. So it's good that I've lost those games, serves me right!