This week's police crackdown at the News of the World comes just months after a hard-hitting report from Information Commissioner Richard Thomas on the trade in confidential information.
In May, Thomas called for jail sentences of up to two years for those who bought and sold secret information — a call which was last month echoed by Lord Falconer.
Thomas said: "The ultimate buyers of illegally obtained personal information include journalists, financial institutions and local authorities."
He said there was "a large scale market in the trading of personal information" and that the penalties are too low to have a deterrent effect.
In one major case investigated by his office, records had been found of secret information being sold to 305 named journalists from a range of newspapers.
Thomas said: "At a time when senior members of the press were publicly congratulating themselves for having raised journalistic standards across the industry, many newspapers were continuing to subscribe to an undercover economy devoted to obtaining personal information forbidden to them by the law."
Press Complaints Commission chairman Sir Christopher Meyer, presenting the PCC's annual report in May, urged journalists to respect the law which says paying for confidential information is illegal.
He said: "We can and do urge on journalists respect for the law — bribery has no place in journalism.
"I will go on urging. And I look forward to discussions with Mr Thomas about what more he thinks the PCC can do about this within the self-regulatory framework.
"But clearly it would not be viable simply to duplicate the criminal law in the Code of Practice."
■ Clause 10 of the Code states:
The press must not seek to obtain or publish material acquired by using hidden cameras or clandestine listening devices; or by intercepting private or mobile telephone calls, messages or emails; or by the unauthorised removal of documents or photographs.
Engaging in misrepresentation or subterfuge can generally be justified only in the public interest and then only when the material cannot be obtained by other means.
Meyer said this week in response to the Goodman arrest: "It is absolutely clear that intercepting private or mobile telephone messages is completely unacceptable under the Code, unless there is a compelling public interest reason for doing so.
"Even then, journalists must also of course abide by the terms of the. The Commission reserves the right to investigate the newspaper's conduct in this case, if, at the end of the legal process, it appears that there are unresolved questions about its application of the Code of Practice."