Key Points:

History is littered with examples of the fearful power of the mob. And of its irrationality and cruelty. It's the reason I've always resisted the superficial appeal of incorporating binding mass referendums as part of our democratic system. The groundswell of sympathy for 50-year-old Manurewa child-killer Bruce Emery on Friday after he was jailed for four years and three months for stabbing a 15-year-old tagger to death only reinforced my lack of faith in the wisdom of the mob.

Surely Emery is paying a very cheap price for someone who admitted running from his house with a 13cm kitchen knife in his hand, chasing the youngster down a street and extinguishing his life with a deadly thrust to his chest. Cheap when you think that 12-year-old Bailey Junior Kurariki, for instance, got locked up for seven years for the same crime of manslaughter - and he didn't even deliver any blows to his victim.

Even Emery, in an interview after his December conviction, admitted "I've created a complete mess" and asked for forgiveness from the youngster's family. As he said to the Sunday News at the time, "I would suggest people in this situation ring the police and stay on your property. For goodness sake don't even try to apprehend them. Just wake up in the morning and clean it off."

Who could disagree with that? Yet the bile-filled and often racist support for the killer that erupted onto the Herald online "your views" was having none of that.

"His greatest crime is that he can support himself and that he's white. There are two levels of justice in this country," said one, who argued Emery should get home detention "at worst".

Chris from Dunedin reckoned "It's a pity Mr Emery didn't get his scumbag mate, too. The little swine was willingly destroying Emery's property for no reason other than that he felt like it. Good riddance!"

From Wanganui comes the preposterous claim that "the tagger was not stabbed but had actually stepped into the knife and provoked Emery". He added that "this sentence sends a message out to all those scumbag taggers that it is ok to tag because the courts will protect them".

Others want to give the killer a medal, one claiming "the silly child deserved what he got" and that "if the tagger wasn't defacing other people's property he would still be alive".

There was a time when my neighbourhood came in for concerted tagging attacks. It was infuriating to come out in the morning and see someone's handiwork decorating walls and fences up and down the street. It went on for months and the council graffiti police and the victims kept washing it off or painting it over.

It was so frustrating. I used to dash to the window thinking I could hear the tell-tale clack of the spray can being shaken. I imagined installing elaborate devices which would pour pots of paint over the miscreants, or hose them down as they set to work. But rushing to the kitchen, grabbing a knife for "protection" then chasing the scoundrels down the street and stabbing them? That never entered my head. To my knowledge, rushing around confronting people with deadly weapons has, to borrow a recent advertising campaign on family violence, never been all right.

Tourists talk about the friendliness of the New Zealanders they meet. But just below the surface there simmers a nasty uncharitable streak that should fill us all with a deep uneasiness. Perhaps it's always lurked there, and it's taken the anonymity of the internet to provide a conduit for it to ooze out. Whatever, it's much more scary to me than the odd tagger abroad at night.

Thankfully, there were a smattering of contributors with whom I could empathise. Rhys from Auckland who, tongue in cheek (I hope) asked "where is the Sensible Sentencing Trust now? Shouldn't they be spurting out about the inadequate sentences of the justice system?"

And from "Sane Aucklander" the last word. "A boy is dead, killed by a man. This man is given four years while the boy is dead forever. This boy had no knife, no weapon, did not threat. This boy did not deserve to die by the knife of this man."