Hindsight can reveal that this strapping young man would go on to become a high priest of New Ireland. Where once folk were encouraged to bring problems to the confession box, now they simply pick up the phone and talk to Joe.

Duffy was thrust centre-stage again in the last 10 days by two incidents that highlight different strands of his Liveline phone-in show on RTE radio. Last Friday week, 41year-old Susie Long died of cancer.

There is strong evidence to suggest that had she been a private instead of public patient, her condition would have been diagnosed seven months earlier, and may not have been fatal. Last January, under the pseudonym 'Rosie', she read out a long letter on Duffy's show, highlighting how the two-tier health system may well have condemned her to death. Later, she revealed her true identity and campaigned on Liveline against the inequities of the system. The two became friends. Duffy dedicated last Monday's programme to her, and was among the mourners at her funeral service that day. The campaign did more to highlight the inequities than a forest of analytical or investigative newsprint would have managed. Many believe Susie Long made a difference after she began talking to Joe.

Two days before Susie's demise, Judge Paul Carney had a little pop at the high priest of the airwaves. Carney finished his address concerning Majella Holohan's victim impact statement with a reference to Duffy's programme.

"In the explosive atmosphere after sentence being imposed, in ignorance of who he was, one of Mr Duffy's researchers approached a court official looking for a comment, " Carney said. "This shatters the myth of Mr Duffy being a kindly old gentleman who sits by his telephone in Dublin waiting for it to ring."

Duffy interpreted the pop as implying he trawled for callers to the programme. On Monday, he rejected that out of hand, but Carney, like a lot of people in power, obviously finds Duffy an irritant, to put it at its mildest. To be fair to Carney, the subject of the criminal justice system is one in which the dangers of a powerful phone-in show become apparent. In a culture where, increasingly, the quality of justice is gauged by the reaction of the victim, and in which the victim's status is decided by the media, phone-in shows can become a forum where rage is released but little light or balance is thrown on the subject. In the area of crime, that can have dire consequences when politicians spot the bandwagon and decide to jump aboard.

Other dangers abound with the live phone-in programme. Earlier this year, RTE had to settle for 250,000 with PR consultant Monica Leech over a lurid allegation that a prankster aired while talking to Joe.

It is also unlikely that Duffy's popularity reaches into Irish prisons at the moment, despite his background as a probation officer. In May, armed robber John Daly couldn't help but phone up and talk to Joe from his cell in Portlaoise.

The call generated a clampdown on mobile phones in the state's prisons, prompting outrage among the inmates.

In most areas, however, Duffy has excelled at facilitating a light being shone into dark corners, where the state or powerful interests are doing down citizens. Whether it be pensioners, home helpers or exploited tenants, talking to Joe has prompted action from the powersthat-be.

"The great thing about him is he is a terrific listener, " says one RTE insider. "He also has a finely tuned journalistic ear and doesn't feel the need to impose himself on the subject." Now 51, this former student revolutionary has managed the difficult feat of retaining a role as a voice of the people, while simultaneously bedding down with the establishment. His pronounced Dublin accent helps, separating him from the standard Donnybrook fare. Born in Ballyfermot, he was among a batch of young people from the working class suburb to scale the citadel of Trinity College in the late '70s. Once inside, he went to work on the revolution. He was elected president of the college's students' union on a ticket with current Labour party senator Alex White.

"Student politics took a sharp turn to the left after they got in, " one former student from the time remembers. "Joe was a big personality. He led some major protests, organised the boycotting of the college canteen, and opened up an alternative outlet for students while it was going on.

"Then there was a problem with the college bar and that was boycotted. The union didn't have a licence to sell drink so Joe decided they would give it away free and rent out the glasses. There were huge crowds at some of those protests, anything up to 1,500 or 2,000 people."

After finishing in Trinity, Duffy stayed in student politics, getting elected president of the Union of Students of Ireland. Like all good revolutionaries, he did some time. He and fellow activists were jailed for a week after occupying the offices of the Department of Social Welfare in a student medical card dispute.

"Some at that time would have regarded him as a bit daft but most would have said he was great, a breath of fresh air.

Others thought of him as a raving lunatic, " another student source remembers.

From the heady world of student politics, Duffy moved to a career in the probation service. Then in 1989, he applied for a job as a trainee producer in RTE and was accepted. He found a slot as a reporter on the Gay Byrne radio programme. Byrne took the young Duffy under his wing, and when the old master drew back from his daily commitment in the mid '90s, Joe was the obvious successor. Things didn't work out. "He just wasn't experienced enough at the time, " a radio source says. "It was a bit of a disaster."

Duffy persevered through other programmes until he was slotted into Liveline in 1999 when Marian Finucane vacated the seat. He has gone from strength to strength since then. In 2005, he was paid 268,000, making him the fourth highest earner among RTE presenters. Last year, he came close to jumping ship. Newstalk dangled even bigger money in front of him. In the end, he stayed, leading to speculation that he never intended to go, but used the offer to secure his position with the state-run broadcaster.

One criticism that has cropped up is his tendency to attempt to get contributors to emote, particularly on a slow news day. However, in a realm where grasping for populist sentiment is a given, Duffy exercises restraint most of the time. Unless he pushes for a move, he is unlikely to be shifted from his prime slot. That means more and more people will be talking to Joe, and he in turn will remain a thorn in the side of the powers-that-be.

CV Name: Joe Duffy Family: Married to June Meehan, father of triplets In the news because: His friend Susie Long died and Judge Paul Carney had a pop at him.

Most likely to say: "Talk to me, set yourself free, emote."

Least likely to say: "Shut it. You're talking rubbish."