Good observation. I have noticed that people very vocal online do not do so well in person. They forget what it's like to have people looking at you disapprovingly or to be forced to express your views coherently the first or second attempt, without the chance to craft the perfect 140 char response.

Unfortunately, as more and more young people grow up with digital spaces as their primary domain, they are losing the ability to communicate in person. I have a few friends that are high school teachers, and they all notice this trend. Every class discussion involves short sentence answers, low effort, very little passion. But if you let them use a digital space to post opinions (like a class discussion forum) things can become polarised, or at least more passionate than they were in class.