"Kill Ian Brady" read one comment underneath an article about the Moors Murderer last week.

"Bring back the death penalty," wrote another.

One reader countered: "Don't let him die, that's what he wants," while another typed: "just knowing that he wants to die and is kept alive makes me happy."

Brady has been force-fed since going on hunger strike more than 10 years ago, a decision that has divided Britain.

Incarcerated in Ashworth hospital he is considered mentally ill and is kept alive by a tube passed through his mouth and into his stomach.

Ian Brady and Myra Hindley are frozen in time for many as few pictures of the murderers have been released since they were sentenced in 1966.

Using taxpayers' money to keep Brady alive may sound repellent, but for a killer whose fetish is control, force-feeding is anathema to him.

"I have to fight simply to die. I have had enough. I want nothing, my objective is to die and release myself from this once and for all. I'm eager to leave this cesspit in a coffin," he wrote in a letter sent to the BBC in December 1999.

A mental health tribunal for Brady was scheduled in July but having suffered a seizure just days before, he was too ill to attend. If he had been sent to prison, he would have been able to starve himself to death.

"Good," insist the masses. "His victims didn't get to choose, why should he?"

"If he wants to die, he should live. If he wants to live he should die."

It's easy to argue that. But it's not right.

Arguments to 'bring back the death penalty' and 'not give Brady what he wants' are flawed by their motivation. Hanging a noose round Brady's neck or shoving a tube into Brady's stomach just because we're angry isn't good enough. Emotion should never be given a place in law.

Punishment is not revenge and a prison sentence can't be couched in such simplistic terms. After all, one of the major purposes of prison is surely to protect society, and revenge is one of the most destructive forces there is.

Killers like Brady challenge our conception of criminal law. It's purpose is to protect life, not end it.

A similar agitation was being waged across Norway as Anders Breivik stood trial. Sentenced to 21 years in jail, with a minimum of ten years, the sentence can be extended if he is judged to be a threat to society.

Breivik is expected to see out the rest of his days at the high security but humanitarian Ila Prison, in conditions which many Norwegians may feel is unfair.

However Ellen Bjercke, senior adviser at Illa Prison, said before the verdict: "I think the loss of liberty is the major punishment regardless of what sort of conditions you have lost your liberty under."

It's an emotive debate. Earlier in the trial a lay judge was dismissed after writing on Facebook that the "Death penalty was the only fair outcome"

Brady and Hindley narrowly escaped the being sentenced to death for their horrific crimes. Between their arrest in 1965 and trial in 1966 the death penalty was abolished.

I can't imagine how it feels to know your child's murderer is living and breathing whilst your loved one's life has been taken away. That Brady continues to live achieves one thing. We still remember.

United through revulsion, his crimes reinstate our desire to protect society's weak and remember the children who will never grow up.

The outpouring of emotion for Winnie Johnson, who died earlier this week having never found the body of her son Keith Bennett who was killed by Brady was remarkable in many ways.

It was more than just sympathy, it was empathy. Across social media, messages were focussed the love of a mother for her son, rather than using her death as a reason to channel anger at Brady.

Ian Brady is a sad old man in prison. Let him not poison our society, but rather focus on protecting what we hold dear - life.