Lord Grabiner QC is the lawyer you saw sitting in a row of seats behind Rupert Murdoch when the newspaper owner gave evidence to a Commons committee last July and ended up with a custard pie in his face. Grabiner was there because he chairs the management and standards committee set up by Murdoch’s News Corporation, the ultimate owner of the News of the World.

The commercial lawyer, a Labour peer since 1999, was brought in to beef up standards after the defunct Sunday newspaper’s involvement in the phone-hacking scandal. So anything Grabiner says on the subject of media intrusion and personal privacy is bound to be of more than passing interest. Delivering the prestigious Lionel Cohen memorial lecture at the Hebrew University of Jerusalem this week, he adopted a measured, even-handed approach to which no public figure - and no newspaper proprietor - could take exception.

The QC began with an unvarnished summary of the inquiry currently being conducted by Lord Justice Leveson (who would, I suggest, be the ideal legal figure to deliver the Lionel Cohen lecture next year). Leveson’s inquiry, Grabiner said, ‘has shown how badly some representatives of the press have behaved, leaving victims stranded in a welter of public hatred or great distress’. Although concerned mainly with press standards, the inquiry had demonstrated ‘the need to uphold a free and independent press on the one hand and respect for an individual’s privacy on the other’.

And that was very much the theme of his lecture. Though privacy had famously been defined as ‘the right to be left alone’, Grabiner regarded it as more of a human value than a legal right. It was all about choice. In the words of a New Zealand judge, ‘only a hermit or an eccentric wishes to be utterly separated from human society. The ordinary person wishes to exercise choice in respect of the incident and degree of social isolation or interaction’.

What, though, of the argument that some of us have forfeited our right to choose, either by entrusting our private information to Facebook or because we have achieved some sort of public profile? Isn’t an individual’s discomfort the price we pay for a free press? Certainly, Grabiner acknowledged, the discomfort suffered by MPs and peers who were exposed as having abused the parliamentary expenses system was an ‘inevitable and welcome concomitant of true investigative journalism’. But it didn’t follow that individuals who’d had details of their intimate relationships divulged in the tabloids to satisfy prurient curiosity should simply ‘grin and bear it’.

Where, then, is the line to be drawn? Grabiner’s answer, inevitably, is that there is no ‘bright line’: an activity is not private simply because it is not carried out in public just as activities are not open for publication simply because they are not carried out behind closed doors. Similarly, having a public profile does not mean you have lost the right to privacy altogether. The balancing exercise is ‘inherently fact-sensitive’.

Grabiner contrasted the US, which gives primacy to freedom of speech, with France, where privacy has a large measure of protection. He placed Israel and England somewhere in the middle, though Israel allows arrested defendants a temporary measure of anonymity that would not be tolerated in the common law jurisdiction from which much of its legal system is derived. Very reasonably, in my view, the QC came down in favour of a system that allowed judges to weigh the competing arguments for and against publication in individual cases. ‘If we err too heavily in favour of protecting privacy, we risk destroying one of the most fundamental freedoms known in a civilised society,’ Grabiner concluded. ‘But if we accede to the media’s cry that judicial intervention in favour of an amorphous "right to let alone" smacks of censorship, we risk giving birth to a culture of transparency where, among our moral custodians, would be those responsible for the phone-hacking scandal.’

That’s fine. But the view that we can trust judges more than journalists has been undermined this month by an extraordinary decision from the attorney general for Northern Ireland, John Larkin QC, who, unlike his English counterpart, is not a politician. At the end of last month, Larkin announced that he had been given permission to bring proceedings for contempt of court against the Labour MP and former secretary of state Peter Hain and Biteback Publishing, which recently published Hain’s memoir Outside In. A hearing is listed for next week.

According to Hain, Larkin had argued that passages in the book ‘constitute unwarranted abuse of a judge in his judicial capacity that undermines the administration of justice in this jurisdiction, and consequently constitute a contempt of court’. Hain says this relates to his criticism of Mr Justice Girvan, now Lord Justice Girvan, over a decision the judge had made in 2006 quashing Hain’s appointment of an interim victims’ commissioner.

I have not read Hain’s book and cannot say whether his remarks were inappropriate. If they were, I would have expected others to have sprung to the Northern Ireland judge’s defence. Girvan might even have sued for libel in the English courts.

But it will be assumed that Larkin sought the judge’s views before launching proceedings. The attorney general was unwise to bring the matter before Girvan’s fellow judges. If they are seen as using obsolete and ill-defined common law powers to restrict the media’s right to freedom of expression on matters of public importance, the administration of justice will be much more seriously undermined.