A former News of the World journalist told Britain's phone-hacking inquiry the practice was "perfectly acceptable", while a reporter who helped reveal the scandal accused some media of bullying.
On a day when the Leveson Inquiry into media ethics switched its focus from alleged victims of hacking to journalists, the probe heard tabloid journalist Paul McMullan defend hacking as a legitimate means to obtain stories.
McMullan, the News of the World's deputy features editor between 1994 and 2001, said the British public were the "judge and jury" of what was acceptable -- and had bought the paper in their millions.
"All I have ever tried to do is to write truthful articles and to use any means necessary to try to get to the truth," he said.
"Sometimes you have to enter a grey area that I think we should sometimes be applauded for entering, because it's a very dangerous area.
"My life has been at risk many times, at home more than in war zones. I used to get a death threat at least once a month for 15 years of my career."
But he also bitterly denounced former News of the World editors Rebekah Brooks and Andy Coulson, who later became Prime Minister David Cameron's media chief, saying they had falsely claimed ignorance of the practice.
"They should have had the strength of their conviction to say, 'Yes, sometimes you have to enter into a grey area, or indeed a black, illegal area for the good of our readers, for the public good.
"Instead... they said 'oh, we didn't know they were doing that'.
"They're the scum of journalism for trying to drop me and all my colleagues in it."
He added: "Phone hacking is a perfectly acceptable tool -- given the sacrifices we made -- if all we are trying to do is to get to the truth.
"I didn't think anyone realised that anyone was committing a crime at the start," he said of the practice.
McMullan went on: "In 21 years of invading people's privacy I've never actually come across anyone who's been doing any good.
"Privacy is evil," he argued. "It brings out the worst qualities in people. Brings out hypocrisy. It allows them to do bad things."
McMullan also recalled how he had revelled in tailing public figures before the death of Princess Diana shone a spotlight on the methods involved.
"I absolutely loved giving chase to celebrities, I must admit," he said. "Before Diana died it was such good fun. How many jobs can you actually have car chases in? It was great."
The Rupert Murdoch-owned News of the World tabloid, Britain's biggest-selling weekly paper, was closed down in July amid an outcry about the hacking of a teenage murder victim's voicemails.
Guardian reporter Nick Davies, who helped uncover the scandal, told the inquiry that his sources on newspapers' use of voicemail interception were genuinely fearful of recriminations and preferred to be kept anonymous.
Davies said between 15 and 20 former News of the World journalists had spoken to him or his researcher on condition of anonymity.
"You've got to make these people safe, and the first step almost all the time is a guarantee of anonymity," Davies told the hearing in central London.
"There is a culture of bullying in some Fleet Street news organisations," he said.
Davies said that as a result of the scandal, he now thought the British newspaper industry was not capable of regulating itself.
Newspapers should be required by law to correct demonstrably false stories, giving the corrections the same prominence as the original stories, he argued.