Terrorising the famous is standard fare for Rupert Murdoch’s News of the World. So many would see it as fitting that three men, including the sleazy Sunday tabloid’s royal correspondent Clive Goodman, are being investigated by counter-terrorist police for allegedly intercepting phone calls at Clarence House, the official residence of the Prince of Wales.

Goodman and Glenn Mulcaire have been jointly charged with hacking into the mobile phone messages of Prince Charles’s staff. And the scope of the inquiry has been widened after suggestions that former home secretary David Blunkett, culture secretary Tessa Jowell and other politicians may also have been targeted.

Meanwhile, the Met’s anti-terrorist branch – which is handling the investigation due to “potential security implications” – is probably indulging in a little schadenfreude at NotW‘s expense. When the paper’s notorious undercover reporter Mazher Mahmood, aka the “fake sheikh”, tipped off Scotland Yard two years ago about three men who were supposedly plotting to buy substances for a dirty bomb, anti-terrorist police were obliged to investigate. The men were arrested, only to be acquitted, but not until police had spent about 4,070 hours investigating the allegations. The three-month trial is thought to have cost one million pounds.

And according to former Daily Mirror editor Roy Greenslade, what’s emerged here is one of “Fleet Street’s dirtiest secrets” – that many papers “pay informants to discover phone records, the content of text messages and the recordings of voicemails”, he writes on his Guardianblog.

“With the red-tops losing sales at a fast rate, there is a desperation to cling on to as many readers as possible”, says Greenslade, and it is thought that “ever more intrusive revelations, no matter how trite and no matter how hurtful, are what the public wants.” And yet, “imagine if all the resources and the technological expertise that are devoted to this seedy trade were spent instead on reporting what is happening in Lebanon.”

Indeed. In the meantime, perhaps the royal family should consider upping the security on mobile phones. Right now, it’s relatively simple to hack into someone’s mobile telephone message service by simply calling up their voicemail and using what is called a “default” code, says The Independent. And these are easy enough to decode – many range from 4444, 1234 to even the last four digits of the target phone. Even if users have changed their Pin, says The Guardian, “it is often to something little more imaginative than their date of birth”.

With people wising up, “paying people for their stories will become more important”, says a former tabloid reporter. Or maybe reporters will have to revert to that time-honoured tabloid tradition: rifling through bins.