As newspaper bosses decide to close the News of the World in the midst of a storm over phone hacking, what are the key questions it poses?
What has News International announced?
Sunday, 10 July, will be the last issue of the News of the World (NoW).
It will contain no commercial adverts. Any advertising space will be donated to charities and all of the edition's revenue will go to good causes.
How has the government reacted?
The prime minister's office said it had no role or involvement in the decision to close the paper, and no pressure was applied to News International or its chairman James Murdoch.
The PM announced two inquiries - a judge-led one into phone-hacking allegations to start once the police investigation is over, and another looking at newspaper ethics.
The Press Complaints Commission (PCC) will be scrapped.
What is the latest on the police investigation?
Two arrests have been made. Andy Coulson, a former NoW editor and ex-director of communications for David Cameron, was arrested on 8 July by police investigating phone hacking and corruption allegations. He has previously denied any knowledge of phone hacking.
Ex-NoW royal editor Clive Goodman, jailed in 2007 for phone hacking, was arrested over corruption claims.
Meanwhile, police have identified 4,000 possible targets and are planning to contact all of them.
How did the scandal arise?
The NoW has been illicitly hacking into the voicemail messages of prominent people to find stories.
It admitted intercepting voicemails in April after years of rumours that the practice was widespread and amid intense pressure from those who believed they had been victims.
So far, one NoW journalist and a private investigator have been jailed for hacking.
What is the News of the World?
A national tabloid newspaper published in the UK, famed for celebrity scoops. Its fondness for sex scandals gained it the nickname "News of the Screws".
Its sales average 2,812,005 copies per week.
The NoW is published by News Group Newspapers, part of News International, which is a subsidiary of Rupert Murdoch's News Corporation.
Who is alleged to have been hacked?
Police have a list of 4,000 possible targets. Among them are royal aides, celebrities, sport stars, politicians and victims of crime.
They include actor Hugh Grant, publicist Max Clifford, actresses Sienna Miller and Gwyneth Paltrow, former MP George Galloway, Lord Prescott, London Mayor Boris Johnson, football pundit Andy Gray and ex-footballer Paul Gascoigne.
Murdered teenager Milly Dowler and the parents of murdered Soham schoolgirls Holly Wells and Jessica Chapman were allegedly targeted. Relatives of dead UK soldiers may also have had their phones hacked.
Milly Dowler Claims that Milly Dowler's phone was hacked were described as "truly dreadful" by the prime minister
How did the NoW hack phones?
Mobile phones used to come with a default four-digit Pin such as 1234, 0000 or 3333. Customers were expected to change their Pin, but very few did.
Tabloid journalists and private investigators could simply ring the number and if the caller didn't answer, enter the default Pin and access the person's messages.
Another ruse was to change the voicemail Pin from the default to prevent other journalists having access to it.
Why did the NoW hack phones?
For exclusive stories.
Competition is fierce among the national press and, under intense pressure, reporters can push at legal boundaries.
How do we know who was being hacked?
The NoW's royal editor Clive Goodman and private investigator Glenn Mulcaire were jailed for hacking in January 2007 after it was found they targeted Prince William's aides. It stemmed from a NoW story published in November 2005 about the prince suffering a knee injury.
Detectives recovered files from Mulcaire's home which referred to a long list of public figures and celebrities.
In 2009, the Guardian newspaper claimed NoW journalists had hacked the phones of up to 3,000 celebrities, politicians and sports stars. Police confirmed suspected victims had been identified among royals, the government, police and the military. Police also released some of the names. Other people claiming to have had their phones hacked have spoken to the media.
Actress Sienna Miller Sienna Miller is one of the hacking victims to have taken legal action
Why does phone hacking matter?
It is against the law. If NoW bosses authorised phone hacking then they could face charges.
But the scandal also goes to the very heart of the relationship between the government and police and the UK media.
It raises wider questions of ethics in the press and how the police have investigated hacking.
Police are also facing questions over the relationship between its officers and the papers. News International uncovered e-mails apparently indicating tens of thousands of pounds were paid over the years to police. Celebrities and politicians whose phones may have been hacked have long criticised police for failing to properly investigate and for being too close to the media.
The relationship between politicians and Rupert Murdoch's newspaper empire is also under close scrutiny. Media commentators have argued that for the past two decades no politician with any prospect of power has dared to attack his empire.
The appointment of Andy Coulson, the editor of the NoW at the time Goodman and Mulcaire were operating illegally, as David Cameron's director of communications has also thrown into question the prime minister's judgement.
And the phone hacking scandal could also dent Rupert Murdoch's ambitions to take control of BSkyB.
What are the victims doing about it?
Several cases have been settled in the courts. Sienna Miller won £100,000 damages and Andy Gray received £20,000. Max Clifford brought a private case and received a reported settlement of £700,000.
Other victims are awaiting the outcome of police investigations or have already launched legal action.
Lord Prescott Former Deputy Prime Minister Lord Prescott has said he believes he was targeted by hackers
What is the history to the police investigation?
The Metropolitan Police has faced criticism for their initial inquiry in 2006 into phone hacking at the paper. It saw Goodman and Mulcaire jailed but did not implicate anyone else.
In 2009 the Met chose not to relaunch their investigation despite claims in the Guardian that the NoW was involved in widespread phone hacking of several thousand celebrities, sports stars and politicians.
But, in January 2011, amid continuing pressure, the Met reopened the investigation and launched Operation Weeting to look at "significant new information". On the same day the NoW sacked Ian Edmondson, one of its assistant editors, when four e-mails relating to phone hacking were allegedly found on the newspaper's systems.
Those arrested and bailed by police as part of the new investigation included Mr Edmondson, NoW chief reporter Neville Thurlbeck, senior NoW journalist James Weatherup, freelance journalist Terenia Taras and Press Association journalist Laura Elston.
In May, former Deputy Prime Minister Lord Prescott, Labour MP Chris Bryant, ex-Scotland Yard commander Brian Paddick and journalist Brendan Montague won a High Court bid for a judicial review into the police inquiry.
How is hacking linked to alleged payments to police?
Commentators and victims accused the police of a lack of will to investigate hacking because officers were too close to the media.
At the beginning of July, News International handed over e-mails which were said to show payments were made to police in return for information, and they were alleged to have been authorised by Mr Coulson.
Met Commissioner Sir Paul Stephenson said a small number of officers were alleged to have taken illegal payments, and if true, they would face a criminal court.
Much earlier, in 2003, Rebekah Brooks, News International's chief executive, admitted to a Commons committee that journalists had paid police for information in the past. But she later said she had no knowledge of "any specific cases".
What has the government done?
The prime minister promised an inquiry into phone hacking after revelations in July that bereaved families may have been targeted. The government, and the previous Labour administration, were accused of being slow to react.
After the Guardian's claims in 2009, the cross-party House of Commons Culture, Media and Sports Committee interviewed News International bosses, including Mr Coulson, over the newspaper's accusations..
In its report in February 2010, the committee accused the NoW of "collective amnesia". MPs found no evidence that Mr Coulson had either approved of phone hacking by his reporters or was aware that phones were being hacked but said it was "inconceivable" that no-one else knew it was going on.
How did News International initially respond?
News International initially denied phone hacking was widespread and put Goodman's conviction down to the work of one "rogue reporter". Editor Andy Coulson resigned but claimed no knowledge of hacking.
It was only after intense pressure from victims that it admitted, in April this year, that hacking was used. On 10 April an official apology was made on the NoW website and on page two of the newspaper for intercepting voicemails between 2004 and 2006. It said its past behaviour was a "matter of genuine regret".
News International instructed lawyers to set up a compensation fund of £20m to deal with "justifiable claims". It has made several payouts.
The company said it would be "horrified" if claims murder victims or bereaved soldiers' families were targeted are true.
News International has welcomed the prime minister's pledge for a wide-ranging inquiry into standards in the media. It also pledged to co-operate with the police inquiry.
What about Andy Coulson?
Andy Coulson Andy Coulson blamed coverage of the phone-hacking story for his resignation
Mr Coulson was editor when Goodman and Mulcaire were convicted. He resigned, saying he took responsibility for something that had happened on his watch.
But in November 2010 detectives interviewed Mr Coulson as a witness - and two months later he quit his post at Downing Street, citing coverage of the scandal.
In July, he was arrested by appointment at a south London police station and police were searching his south London home.
These events led to questions about the judgement of David Cameron. Asked if he had "screwed up" on the decision to employ Mr Coulson, Mr Cameron said: "People will decide."
What about BSkyB?
Rupert Murdoch's News Corporation wants to take over broadcaster BSkyB.
News Corp already owns 39% of BSkyB, but last year signalled its intent to to take over the remainder of the company.
News Corp's bid had faced opposition from rivals in the media industry and some politicians, who objected on the grounds that it would own too much of the British media if the deal went through.
That opposition has increased as the phone-hacking scandal escalates, with critics claiming that it shows that News Corp is not "fit and proper" to own the broadcaster, as required by the media regulator Ofcom.
It looks likely that Culture Secretary Jeremy Hunt will delay his decision on whether to allow News Corp's bid after receiving 100,000 submissions on the issue.
Where does all this leave News International?
News International is co-operating with a police inquiry into hacking and is conducting its own investigation into the claims.
Calls have been made for Rebekah Brooks, editor of the News of the World at the time of the alleged hacking of Milly Dowler's phone, to resign from her current job as chief executive of News International.
In the lead up to the NoW closure announcement, a string of businesses suspended or cancelled advertising with the paper. Among them were Co-operative Group, Lloyds, Halifax, Vauxhall, Virgin Holidays, Sainsbury's, O2, carmaker Ford and the government. The Royal British Legion also cut its ties with the paper as its campaigning partner and put its advertising with News International under review.
Shares in News Corporation have also taken a hit.