"When is an Englishman's home not his castle?"
That is the sub-head with which much of the popular press has turned the fate of Tony Martin into a cause celebre.
But for the legal world, that has always been an over-simplification.
In November 2001, a jury took only 15 minutes to clear a householder who had fatally stabbed an armed intruder in his home
It is the issue of reasonableness which has been at the heart of this case since Martin's prosecution in 1999.
At his trial in 2000, a jury had to decide whether his behaviour in shooting a teenage burglar on his property was reasonable.
And today, a High Court judge was asked to decide if the parole board had acted reasonably in refusing to approve an early release for Martin.
The key to Mr Justice Maurice Kay's ruling lies in the remit of the parole board when considering the release or recall of prisoners serving a determinate sentence.
The primary consideration is the risk to the public.
And although the board will also look at the benefits to the offender of an early release, the balance will invariably be tilted towards public protection.
Thus, the board was not acting irrationally in placing weight on probation reports that Martin might use excessive force again.
Although the board will also look at the benefits to the offender of an early release, the balance will invariably be tilted towards public protection
This is even though the judge who sentenced him said he thought it unlikely that the farmer would re-offend.
In reaching this view, the board will also have been influenced by evidence that Martin has shown no contrition for shooting 16-year-old Fred Barras at his farmhouse in Norfolk.
That, then, is the legality. What, though, of the "common sense", as many others would put it ?
Those members of the public who might be put at risk by an unrepentant Martin may well be burglars.
Do they have the same rights as citizens going about their lawful business ? No, they do not.
According to the law (Criminal Law Act, 1967), "a person may use such force as is reasonable... in the prevention of crime".
Indeed, in November 2001, a jury took only 15 minutes to clear a householder who had fatally stabbed an armed intruder in his home.
But the circumstances in which Martin killed Fred Barras were different.
In addition, evidence presented at his appeal that he suffers from a paranoid personality disorder will also have done him no favours with the parole board.
His consolation is that his release is delayed only until the end of July when he will be freed on licence having served two-thirds of his sentence.