30/07/2013 12:42 BST | Updated 29/09/2013 06:12 BST

Why did a Jane Austen portrait engender such madness ?

Now it's the turn of Walthamstow MP Stella Creasy to receive vicious on-line attacks from internet trolls after giving her backing to journalist Caroline Criado Perez who persuaded the Bank of England to put Jane Austen on the new ten pound note in 2017 rather than Winston Churchill.

A portrait of Jane Austen on the new Bank of England ten pound note will be a refreshing change to Winston Churchill and clearly Mark Carney the new Governor of the Bank of England thinks so. Caroline Criado-Perez victory should be celebrated. In its context it's no big deal so why the fuss, why the explosion of vicious and obscene internet online attacks ?

The emergence of the internet troll shouting demonic-like (or should I say writing) in the seclusion of their own world is a manifestation of the internet era. Twitter has a global reach and level of activity and this freedom can and does have hellish results. Such attacks are those of a coward. But what makes a person do it ?

Is it jealousy? Perhaps an out-going intelligent person appears as a threat. In reality the melting pot of ideas is what progress is all about. Disagreeing with the idea or action doesn't mean it's a threat. If you do disagree and feel there's been an injustice then begin your campaign in a manner that doesn't depend upon aggression and violence designed to humiliate and destroy.

Feelings of inadequacy and inferiority can possibly engender irrational behaviour but are all internet trolls inferior and inadequate people ? They presumably need to humiliate, hurt and try to destroy their targets. Is this internet behaviour directed mainly at women ? I hope not. I assume not.

Free speech is one of the cornerstones of a democracy but Twitter needs to look carefully at their security policies and the police need to take action. It's no comfort but at least you can see the marauding street thug but with the internet troll it's an unseen presence.

Mary Beard the Cambridge classicist whose wonderful journeys across the Roman world for the BBC have reinforced her status as the queen of that world re-tweeted the highly offensive posts she'd received and suggests that exposing the trolls is the best tactic - name and shame. Were the trolls jealous of such a talent ?

What is clear is that such aggression cannot be tolerated.