Well, firstly I never seriously suggested we systematically do anything to trolls as a form of real justice.
Secondly, you ( and other people) shape society's culture and norms. Trolling is a matter of culture, not just law, and it is not simply the governments responsibility or not. The people pass laws which the government enforces (or at least that's how its suppose to work in a democracy).
Thirdly, I actually made the same comment as you the other day, regarding "don't take internet comments seriously". Here's a great reply:
I will play the part of the alarmist and also be the first to invoke Goodwin's law by stating that unchecked rhetoric was the first psych-ops that the Nazi's used. Group acceptance of dehumanizing a different group is the first step down a horrible path. It should be checked at every advance. The seed in America seems to have happened with Muslims, as it was acceptable in good company to view them all as fundamentalist psychopaths, the government and media where all to willing to reinforce such group think as it strengthen their case for war, now that the seed has set it has grown to bear fruit. Vilifying or dehumanizing a group of people always leads down a path of darkness. I would not hastily blow it off as being stupid and crap said on the internet, it is a dangerous mindset, that is easily infection to those susceptible to group think and the sewers of it tend to be far too willing to act when they feel emboldened by numbers and the echo chamber.
http://news.ycombinator.com/item?id=3559345