On the 13th of November 2005 the News of the World published a story about Prince William that he and a contact knew was only known to the two of them, there had been another similar story recently, leading the Prince to come to the conclusion that somebody was listening to his or his aides' answer phone messages.  After a seven-month investigation, police tracked the source of some of this activity to the offices of the News of the World, the Sunday tabloid of the Murdoch News International stable.  The police limited their search to the single reporter attached to the prince's story, although in their investigation they had apparently come across lists of thousands of mobile numbers, and a large number of PIN codes for those accounts and receipts for work on many other stories while the investigators were searching the offices of a private investigator used by various papers to provide plausible deniability about the "dark arts" (as they called them).  These dark arts consisted of more than just voicemail hacking, it also consisted of bribing police officers and civil servants at a variety of government agencies and phone companies to obtain private information about individuals.  There was even a case of one of the papers breaking into the offices of a subject of its investigations and installing wireless cameras and microphones in the offices of an associate of someone who was going to be the subject of a story.  Now the investigation revealed that it was the whole spectrum of UK tabloid newspapers that were involved in this activity.  The Murdoch press didn't even have the biggest bill amongst them.  There is a report into Operation Motorman, called What price privacy?, covering the police's investigation of a range of insiders, private detectives, civil servants, and police officers who were supplying illegal information to various journalists.
BBC | BBC College of Journalism Blog - Journalists and illegal information

What Price Privacy?' tells how:

"5.6 ... documentation seized at the premises of the Hampshire private detective ..."

That's to say, one target of Operation Motorman

"... consisted largely of correspondence (reports, invoices, settlement of bills etc) between the detective and many of the better-known national newspapers - tabloid and broadsheet - and magazines. In almost every case, the individual journalist seeking the information was named, and invoices and payment slips identified leading media groups. Some of these even referred explicitly to 'confidential information'."

The information, all illegally obtained and illegally traded, included criminal records, registered keepers of vehicles, driving licence details, ex-directory telephone numbers, itemised telephone billing and mobile phone records, and details of 'Friends & Family' telephone numbers.

The documents seized also included notes, invoices, receipts etc naming the journalists for whom the work had been carried out.

So it appears that the sort of activity that we are witnessing is not just the province of the Murdoch press but was instead endemic throughout the UK media, tabloid and Broadsheet. As further evidence of the widespread activity on the part of the UK Media we have this detail from back in 2002 that David Allen Green has noticed.
New Statesman - What did Dominic Mohan say in 2002?

Ring, a ring a story
How appropriate that the most glamourous event in the showbusiness calender should be sponsored by a phone company. Mohan went on to thank "Vodafone's lack of security" for the Mirror's showbusiness exclusives. Whatever does he mean?

Indeed, whatever could he have meant?

And what was known in the world of showbusiness journalism back in 2002?

What  was known in journalism in 2002? Well there is this quote from the UK Celebrity Gossip website Popbitch

Popbitch

Early in 2002 we were out at a party, talking to a group of showbiz reporters. They were shocked when they found out we didn't know the easy way to get celebrity stories. So they told us how they all did. We printed it in issue 107 - 13th March 2002:

Two hacks call a celeb's mobile. One gets the answerphone, and types in 9, followed by 3333. If the hapless celeb hasn't changed the default access code, the hack gets their messages, and can even delete them afterwards to cover their tracks.

If all the juniors (and it wasn't even the NOTW) knew, we're gob-smacked that the editor of the most successful red-top, who had been a showbiz hack before them, didn't.

In 2007 Clive Goodman, the paper's royal correspondent, and Glen Mulcaire, the private investigator employed by the paper were sentenced after being found guilty.  This was followed by a House of Commons select committee investigation (The equivalent of a US senate committee) where News International management insisted that this was an isolated case committed by a reporter who had stepped outside the boundaries of what was considered proper behaviour for one of their staff.

In the committee's report (Self regulation of the press:HC375)(pdf warning) the committee says

We note the assurances of the Chairman of News International that Mr Goodman was acting wholly without authorisation and that Mr Coulson had no knowledge of what was going on. We find it extraordinary, however, that the News of the World was prepared to apply one standard of accountability to the £105,000 retainer paid to Mr Mulcaire and another, far weaker, standard to the substantial cash payments paid to Mr Mulcaire by Mr Goodman. The existence of a "slush fund" effectively can only further the belief that editors condone such payments--on a "no need to know" basis--as long as they provide good copy.

At this point the committee was under the impression that this activity had really only been the work of the royal correspondent and News international has always maintained this to be the case.  The Metropolitan Police, who had investigated the case, had said that there were only a handful of cases.  The Guardian's examination of phone company records showed that the number were at least 90

A year later however two victims of the acknowledged handful had each been on the verge of taking News International to court.  News International settled with each out of court for large amounts of cash, the two payouts totalling over £1 million between them according to reports.  These two were Gordon Taylor, the head of the Professional Footballers Association, and Max Clifford, a Publicist who acts for a variety of UK celebrities.  The fact that these two had been paid out to by the Murdoch organisation drew attention back to the NOTW claims that the phone hacking was just the action of a single lone reporter, it was remotely plausible that Clifford may have some royal contacts that the paper's royal reporter may have been interested in, but to suggest that he might have an interest in professional football to the extent that he might spend his employer's money on acquiring the players' union head's phone messages rather seems to stretch the credibility of the NOTW's answers.  It must be said however that it may be that these payments may have occurred as a defensive measure to prevent lawyers crawling through the paper's internal documentation, but this would be a remarkably expensive way of preventing such activity.  The publication of the US investigation returned the Met and the Crown Prosecution Service to the original notes.  The police called in the reporters mentioned and, according to their lawyers, questioning them under oath as suspects rather than as witnesses.  Understandably under legal advice they therefore refused to give evidence.  However, senior News International executives refused to be questioned, as they didn't think there was anything they could add to their earlier evidence; and Andy Coulson was questioned without being put under oath.  This was taken to be a little suspicious, but with the appearance of no new evidence, the Met and the CPS had an excuse to shut the investigation down once again.

All was then quiet till the Tommy Sheridan trial in Scotland.  Tommy had formerly successfully sued the NOTW for libel after it published lurid articles about his sex life.  A court case had been winding its way through the legal system charging that Tommy had perjured himself.  And Tommy decided to call Andy Coulson as a defence witness.  Once again Coulson denied any knowledge of phone hacking, for the first time in court, and during a perjury trial.  One would think that if it turns out he perjured himself during a perjury trial, things would not go at all well for him in subsequent hearings.

Quiet then returned, until depositions were made in the Sienna Miller case.  She had been convinced that information must have been acquired for a story about her by hacking, and once she acquired documentation from the police, it appeared that there was solid evidence about another News of the World journalist.  Someone who has risen to the post of deputy editor.  NOTW suspended him and he was then interviewed by the paper's lawyers.  At this point Coulson resigned.  Several news organisations leaped to the conclusion that names had been named, leading his lawyers to issue a statement saying that any suggestion that Coulson had been named by her was highly defamatory.  Unnoticed in the background, the CPS had announced that a barrister would be examining all of the paperwork in the hands of the police.  It is thought that this may be far more of a threat than one individual naming names.

On top of this a new round of evidence had been deposited with the culture, media and sport department.  One of the Sun's former journalists has entered into evidence that he was personally instructed by Coulson to tap people.  This is something that Coulson has always denied.  If the full evidence had been leaked to Number Ten ahead of time, this may also be something that might have been seen to raise intolerable pressure, and so Coulson may have leaped before he was pushed.

This is the first of eight cases that are in the process of coming to court.  Mainly resulting from celebrities who have had to legally fight quite severely to even get the basic information from the hands of the Metropolitan Police.

There are three other major strands of evidence also in existence that are yet to appear.  Firstly (and least likely to appear), a legal firm did a thorough investigation of all available evidence in the possession of the NOTW, this has never been made public or handed over to the police, and could be quite revealing, but as it has been created by lawyers it may be held to be privileged.  The second strand of evidence is a selection of micro-cassettes held by individual News International reporters.  According to a reporter there was a culture of paranoia involved in working there, to the extent that the staff regularly recorded their conversations and phone calls with each other.  At least one of these tapes has come to light, although it doesn't show Coulson actually ordering phone tapping, it does involve him praising the recently sacked reporter and praising him for going to lengths to get a story.  The third strand is a horde of backup computer drives stored in the NOTW's warehouse.  We know that the initial investigation involved looking at 2500 emails, this is an amazingly small amount and we can only assume that it was either just the initial emails from the sacked member of staff – and only the outbound email, legally in the UK an employer only has a right to examine outgoing email, if an individual has personal email that has been sent to an inbound email address then the employer is not allowed to look.  Now employers normally ignore this quirk as they consider it, but you can bet that in this case they have obeyed the letter of the law so they didn't have to find anything embarrassing.  Now they claim to have looked at the entire email system, but one would doubt that that quantity of email would come from more than a single account.

The renewed police inquiry has brought up some interesting details, including the fact that people who have previously asked for information had been misled by the earlier investigators.  An example of this is Lord Prescott
Phone hacking: Lord Prescott named as victim as inquiry widens | Media | The Guardian

The development represents Scotland Yard finally beginning to take the lid off the phone-hacking scandal. More than five years after they first started to investigate the illegal interception of voicemail messages by a private investigator working for the News of the World, the Met announced that its new inquiry would:

* Review all the decisions made by their two previous inquiries.

* Contact thousands of public figures who have never been told that their personal details were recorded by the private investigator.

* Warn some public figures that they had previously been misled when they asked the Yard for information.

Police had been dismissive of Prescott's suspicions that he had been targeted, but the head of the new investigation, Deputy Assistant Commissioner Sue Akers, saw Prescott on Wednesday. He was told that invoices recovered by police showed he was targeted by Glenn Mulcaire, the private eye used by the NoW, who was an expert in phone hacking. They also have notes made by Mulcaire about Prescott, who as deputy prime minister was in possession of highly sensitive information. After his briefing by the police chief, Prescott told the Guardian that previous police investigations had been "completely inadequate".

The main thrust of the investigation is now widening, it appears that there may be a civil complaint brought against another News International newspaper, The Sun, which is the Monday to Saturday equivalent of the NOTW.  The timescale of the complaint means that it is from the time when Rebekah Brooks, the current head of News International's news division was editor.  NI have of course denied this, and Rebekah has denied that this occurred outside the named reporter and investigator at a House of Commons select committee meeting; so there could be a considerable amount of embarrassment and various contempt and perjury charges coming up as the evidence points harder and deeper at the senior management of the News International group.  (And if this all comes out before the final decision is made on the takeover of BSkyB, then it could end up costing the Murdoch empire in the region of £400 million per year, if as a result management staff and processes are seen as being unfit, and so the takeover is banned.)

As of this morning it has been announced that the new police investigation is contacting 1000 people for whom there may be enough evidence that their phones have been hacked.  This is a considerable increase from the original grudging number that the original police investigation came up with.  The new investigation says according to AP that there are roughly 2500 people that will need to be contacted.

Questions that need asking.

Why did the met recognise so few people as probably being hacked in the first place?

Why was the investigation at the NOTW so limited?  After Mulcaire's office had been investigated, it was obvious that the problem ran much wider than one individual journalist.

Why didn't the person leading the investigation subsequently leaving and going to work for NI not ring considerable alarm bells?  Surely this would at least raise a few warning flags.  Not saying that he has done anything, but as a policy surely this raises suspicions that the activity has not been above-board, and so should be thoroughly investigated.

Why are newspapers concentrating so much on minor celebrity news that is so liable to this sort of problem?

How many members of staff at the NOTW were regularly using this method of obtaining stories?

What other papers had such a culture of tapping and privacy invasion through illegal means?