A lawyer has told an inquiry into media ethics of the "euphoria" Milly Dowler's mother felt when she found messages deleted on her daughter's phone.
David Sherborne said interception of the murdered schoolgirl's messages by a tabloid investigator was "despicable".
Mr Sherborne represents 51 alleged victims of press intrusion and has been addressing Lord Justice Leveson's inquiry into media practices in London.
The inquiry earlier heard from the editor of the Guardian newspaper.
Mr Sherborne said Sally Dowler would tell the inquiry in her own words of the "euphoria" she felt when she logged into her daughter Milly's phone and found messages deleted.
He described how the News of the World (NoW) tailed the Dowlers when they went to reconstruct their daughter's last journey.
"Mile of grief" was one of several headlines above articles that intruded on the family's anguish and privacy, he said.
"What kind of ethics can you teach journalists who hacked into the voicemail of a murdered schoolgirl? If the relationship between the public and press is to recover, it must happen now," he added.
Mr Sherborne said the experience of his clients was "primarily and largely" at the tabloid or popular end of the press but "it is the whole of the press that stands in the dock".
The lawyer said the media had tried to influence politicians and persuade them that less regulation would make journalism better.
He said the press had a "self-serving agenda" and accused it of buying, stealing and making up stories.
"The press have a very powerful voice and should not be able to drown out the voice of the victims," he warned.
"A number of individuals have already been vilified for agreeing to share their experiences with this inquiry."
Mr Sherborne said police had pointed to over 2,000 tasks relating to the NoW in notebooks belonging to Glenn Mulcaire - the private investigator jailed in 2007 for illegally accessing the voicemails of royal aides for the tabloid.
He said this suggested that over the four years the notebooks covered, each edition of the tabloid could have had around 10 stories a day based on phone hacking "even leaving aside the other dark arts practiced by the newspaper".
The inquiry had previously heard that Mulcaire's notebooks suggested at least 28 NoW journalists commissioned the investigator to hack phones.
But Neil Garnham QC, representing Scotland Yard, challenged the claim on Wednesday, saying police could not confirm all 28 named in Mulcaire's notes were employed by the Sunday tabloid.
Mr Sherborne said the newspaper's stories were built on "manifestly unholy and indefensible ground" and the number of stories "must surely raise questions about who knew what and what level".
The "tangled web" that had subsequently been spun, he said, had "revealed at the very least that someone somewhere is not telling the truth".
Hacking victims were not always well-known people, he said, but were sometimes just involved with or friends of those in the public eye.
He alleged the NoW had also targeted other journalists "albeit broadsheet ones". "The press are even prepared to turn on their own."
The lawyer likened self-regulation by the Press Complaints Commission to "handing the police station over to the mafia" and said it was time for "real change".
He also told the hearing:
- Sara Payne, mother of murdered girl Sarah, was told her phone - given to her by the NoW - was probably hacked by Mulcaire, a "sickening postscript, perhaps a new low" for the paper
- The Nazi-themed NoW story about ex-Formula One boss Max Mosley attending an orgy was "a preconceived story for which they needed the facts to fit". NoW reporter Neville Thurlbeck instructed one woman at the party how best to capture Mr Mosley in a "Sieg Heil" salute - which never happened
- The NoW story of singer Charlotte Church's father having an affair came from phone hacking and almost led to her mother's suicide. The paper also revealed Charlotte was pregnant before she had told her parents
- Footballer Paul Gascoigne's wife Sheryl was portrayed as a calculating wife after their divorce
- The private diary of Kate McCann - mother of missing girl Madeleine - was published by the NoW when her husband had not even seen it. The treatment of the McCanns was a "national scandal"
- Christopher Jefferies, the Bristol landlord of murdered architect Joanna Yates, was accused by various tabloids of being her killer using a "frightening combination of slur, innuendo and dirt-digging" all of which was "nonsense"
- Presenter Anne Diamond was continually hounded by The Sun and NoW
- JK Rowling's children were harassed despite "great lengths" by the author to attempt to keep a private life
- An emergency injunction was granted last week to prevent the harassment of the mother of actor Hugh Grant's child
Earlier, Guardian editor Alan Rusbridger told the inquiry it was important it looked at the 18 months after News International's "so-called rotten apple excuse" had exploded.
Mr Rusbridger referred to "dogs that didn't bark", asking why it took four inquiries before phone-hacking allegations were taken seriously.
He said the events leading up to Lord Justice Leveson's inquiry had been "shocking and immensely damaging".
Lord Justice Leveson told the hearing he was "starting to get to grip with solutions that work for everybody".
He said he would like to see some sort of mediation system that ran in parallel to the courts.
Prime Minister David Cameron established Lord Justice Leveson's inquiry after revelations that the voicemail of Milly Dowler may have been hacked by the NoW while the schoolgirl was missing.
After the conclusion of the police investigation into NoW phone hacking, and any resultant prosecutions, a second phase of the inquiry will examine the extent of unlawful conduct by the press, and the police's initial hacking investigation.
The inquiry later finished for the week and will resume on Monday.