The end of prank calls?
The death of the nurse Jacintha Saldanha has put the business of hoax calls under the spotlight. Where is the line between humour and cruelty?
Hoax calls - where someone winds up a friend or colleague by pretending to be their boss or an important person - are almost as old as the telephone itself.
They have been a staple of TV and radio entertainment programmes since the 1950s when American comedians Steve Allen and Johnny Carson began making them on the Tonight show.
There are numerous examples of rich and powerful people being hoaxed. The Queen in 1995 spent 17 minutes talking to a man she thought was the prime minister of Canada. It was actually Pierre Brassard, a Canadian radio presenter and impressionist.
In 1998, Prime Minister Tony Blair took a call from a man claiming to be William Hague, leader of the Opposition. He immediately realised it was a hoax but took it in good humour. It was DJ Steve Penk's idea to try and get past the Downing Street switchboard and the caller was impressionist Jon Culshaw.
Foreign Secretary Margaret Beckett in 2006 thought she was taking a call from Chancellor Gordon Brown. It was actually impressionist Rory Bremner.
Cuban leader Fidel Castro unleashed a volley of abuse after being hoaxed in 2004 by a Miami radio station presenter pretending to be Venezuelan President Hugo Chavez.
But after the death of Jacintha Saldanha, days after putting through a hoax call to the Duchess of Cambridge's nurse, will people think twice before hatching such a prank?
Some say the game is up. Penk, who carried out hundreds of "wind-up" calls at Capital FM, says the recent tragedy will make it almost impossible for these pranks to continue.
"This will kill it, stop the art of winding people up." Comedy has become more politically correct in recent years and in the wake of the phone-hacking scandal there is a move to control the media, he says.
"Ofcom [the broadcasting regulator] are going to wrap it up in so much red tape it'll be almost impossible to get it on air."
Robin Galloway, a DJ on Glasgow's Clyde 1 radio station, has hoaxed Donald Trump, Paris Hilton and Jedward in the past. He has responded to the death of Jacintha Saldanha by suspending prank calls and withdrawing adverts for his Christmas compilation.
"I cannot see me doing them for the foreseeable future," Galloway says. But the outcry over the Australian hoax call will not necessarily end these calls forever. The public will move on and things may return to normal, he suggests.
"When they work, they work tremendously and the audience loves them."
Looking back on the time the Queen spoke to him in fluent French about her views on a forthcoming independence referendum in Quebec, Brassard says politics was not the point of the exercise.
"We didn't do it to extract any secret information. We did it to have fun."
His reaction to news of Jacintha Saldanha's death was "shock, like everybody else, trying to work out the reason why this person killed themselves".
"Thank God none of our prank calls turned out that way."
The Saldanha case shows how badly jokes can backfire, particularly when "ordinary" people are drawn into them.
Victims of hoaxes will often react with anger, says clinical forensic psychologist Michael Berry. They may also be embarrassed, ashamed and believe they've let others down. If they do a vital job, they may resent having their time wasted. They may trust the public less in future.
So is there a line that should not be crossed when making hoax calls?
There's a clear difference in calling someone famous and a member of the public. Jacintha Saldanha was a nurse doing her job in a hospital, whereas Blair or Beckett are public figures used to the limelight.
Penk, who now owns Revolution FM, says most of his calls have been to ordinary people. The key thing is that the people are nominated by family or friends and that the audience is in on the joke. After the reveal, the victim of the prank turns from "100% anger to calm in about 30 seconds," he says.
Conservative MP David Amess was one of those duped by satirist Chris Morris's Brass Eye, in a spoof documentary warning about the dangers of a fictional drug nicknamed "cake".
There is no place for hoaxing, he says.
"I totally condemn it. I could not see anything funny about a girl losing her life because of drugs."
The same is true today of the Australian DJs calling a hospital where a pregnant woman is being treated, he says. "What's funny about it? It's pathetic."
Galloway says he wouldn't have gone near the Australian prank. It would have "tied up a hospital phone line", he argues, and it would have felt wrong to send up a pregnant woman, especially when the duchess was unwell.
Penk says ringing a hospital where a royal is being treated is a "delicate" matter. But he thinks it's just the kind of stunt he might have done. Like the Tony Blair hoax, the entertainment value is in trying to get through the switchboard. "It was pantomime, you have the corgis in the background. I thought 'good on yer' for having the idea."
And no-one could have foreseen the nature of the reaction of the nurse transferring the call. It is harsh to blame the Australian DJs, he suggests. Nobody knows the full circumstances of the nurse's death.
A key question in any hoax or prank is whether the "victims" give retrospective permission for broadcast.
The rules in the UK would have prevented the unauthorised use of the Australian clip without the consent of those featured. Ofcom rules say unless there's a public interest, consent is necessary.
Berry says there's always a dilemma with humour. For him the royal clip was funny. "I genuinely thought it was very funny. It's a great joke that should never have come off." People at the time thought it was funny. It is only in the wake of Jacintha Saldanha's death that people changed their minds.
To take a previous example, the Blair-Hague hoax, the Downing Street switchboard staff would clearly have been embarrassed.
The final woman who puts the call through says to the fake Hague: "You didn't sound like yourself... we do get a lot of impostors you see."
"Hague" replies that they have the same problem at his office. She replies: "You're better now. You sound normal" and puts him through. But Blair saw the funny side and the episode is only remembered for its humour.
It's a sign that hoaxing is an unpredictable business, and that judging where the line falls is more of an art than a science.