Face-rage

Now, so many people share so much of themselves on social media sites, an odd phenomenon seems to have started.
I've decided to call it Face-rage.
What happens is that someone gets very cross about other people's behaviour and rages about their behaviour on their status/tweet /etc. This is usually directed at one person and usually a friend of the person face-raging, but it can also be a boss, rival or ex-partner. I've even seen ones where the rager doesn't even know who the person is.
The rage itself ranges from passive-aggressive to borderline abuse/trolling.

Here's my question.
What benefit is there in this spleen venting?
Does it actually makes us feel better or (as I suspect) fuel the anger/bitterness all the more.
I doubt the person referred to (the ragee if u like) will ever see the comment and think “That's a very good point. Perhaps I should change my future behaviour.” So what is the point?
I would argue that it actually says more about the rager than the ragee, but what do you all think?
Should we just talk to person who has wronged us or is this the best way to express our feelings?