"A single unauthorized leak" is not "sufficient to warrant suppression of the entire investigation," Ellis wrote, citing reports about the case that ran in the New York Times and the Miami Herald.

Federal prosecutors declined to comment on whether the leak investigation has begun, and a spokesman for CBS News declined to comment. Ellis has instructed prosecutors to report to him on the status of the inquiry by Sept. 15.

Attorneys for Rosen and Weissman also declined to comment yesterday, but sources familiar with the case said they have been arguing in numerous sealed motions that the leaks violated their clients' rights and could prejudice potential jurors against them.

Rosen and Weissman were charged last year with violating the Espionage Act in what prosecutors call a conspiracy to obtain classified information and pass it to members of the media and the Israeli government. They are former employees of the powerful American Israel Public Affairs Committee, or AIPAC.

The lobbyists are the first civilians who do not work for the government to be charged under the 1917 espionage statute with orally receiving and transmitting national defense information. Court documents say the information covered subjects including the activities of al-Qaeda and possible attacks on U.S. forces in Iraq.

The case has alarmed First Amendment advocates and some lawyers, who say it criminalizes the type of information exchange that happens every day among journalists, lobbyists and others in Washington. Prosecutors have argued that disclosing sensitive defense information could harm national security.

Federal authorities are conducting a number of investigations of leaks of classified information to journalists, and legal experts said Ellis's order is noteworthy because it is unusual for a judge to initiate such an inquiry.

"It's one of the first tangible signs that the view of the Bush administration, that journalists are not immune from prosecution for trafficking in classified information, might have currency with some federal judges," said Rodney A. Smolla, dean of the University of Richmond Law School and an expert on First Amendment law. He said it is an "open question" whether federal law allows for the prosecution of journalists for publishing classified information.

The possibility of such prosecutions has swirled around Washington since the New York Times broke a story in December about the National Security Agency's surveillance of terrorist-related calls between people in the United States and abroad.

Attorney General Alberto R. Gonzales has suggested publicly that New York Times journalists could be prosecuted for the NSA articles, and federal authorities are investigating other possible leaks that led to reports in The Washington Post about secret CIA prisons, law enforcement and intelligence officials have said.

Ellis, meanwhile, may have further opened the door to criminal prosecutions of reporters with another recent ruling, legal experts have said. The judge rejected defense arguments to dismiss the indictments against Rosen and Weissman, saying that they -- and others -- can be prosecuted if the government thinks they disclosed information harmful to national security.

As a result, drink sales have dropped by more than 10% and even food sales are down 3%, the SLTA said.

Pubs with no outdoor area are suffering the most as their customers stay at home or go elsewhere. Four percent reported an increase in business with their regulars, while 64% saw a decrease.

By contrast, some outlets with good smoking facilities have done well - or at least held their own.

Lynn Adams of the George Bar in Hamilton said: "I think on the whole things could be a lot worse for me in my pub.

"My outdoor area has helped a lot and trade is ticking over but, as my smoking customers say, what happens when winter arrives? This is when we will really feel it."

Paul Waterson, the chief executive of the SLTA and the owner of the Flagship Hotel group, said: "Our members have done an excellent job enforcing the ban and many are now paying for it with their livelihoods.

"These results bear out what we have been hearing - many operations have been hit and some are suffering significant downturns in business."

The SLTA had been sceptical of claims that a smoking ban would help business by attracting non-smokers to pubs. Today's survey will only strengthen those preconceptions.

"Our members are paying for an ill-judged and hasty government policy," Mr Waterson said.

"If this measure is going to save millions in health costs, as we are told, it would be good to have some of this back in compensation for our members who may lose everything."

England plans to introduce its own smoking ban next summer.

The pub group JD Wetherspoon has already introduced some non-smoking pubs in England in anticipation of the government's smoking ban.

But the company delayed making all of its 650 pubs non-smoking after a sharp drop in sales at its 49 smoke-free outlets.

Wetherspoon, however, reported an initial rise in sales at its Scottish pubs after the smoking ban, thanks to a heavy marketing campaign.

Jim Clarke, the finance director at Wetherspoon, said it was premature to come to any conclusions about the smoking ban.

"Although the ban in Scotland has been in place for five months, we need to see the impact in winter," he said.

"In the summer people are quite happy to smoke outside, but we don't know whether that will be the case when it gets cold."

US broadband providers, such as AT&T and Verizon, which ferry data packets along fibre-optic cables, have recently started selling services such as video and voice-over IP (VOIP), sparking fears that these companies could slow down data packets from competing providers such as YouTube and Skype. However, there is currently no way to monitor whether deprioritisation is actually occurring, and a US Senate committee recently rejected draft "net neutrality" legislation that would outlaw deliberate "packet deprioritisation", in which packets get bumped down the transmission queue (www.newscientisttech.com/article/dn9435.html).

Deliberate deprioritisation is hard to detect because there is always a chance packets can be shunted to the back of the queue non-maliciously when there is heavy traffic, says Tom Evslin, a technology consultant based in Stowe, Vermont. His solution is to use the distributed approach to single out deliberate deprioritisation.

Each volunteer would download software that triggers their computer to send out test packets called pings to various websites. Because pings automatically trigger a return packet, they can be used to measure the speed of a connection between two computers. Each probe PC reports its results to a central server that can then work out from all the ping times whether packets from certain websites are being deprioritised, and if so by which broadband providers, says Evslin. He outlined the idea at the Harvard Berkman Center for Internet and Society in Cambridge, Massachusetts, on 8 August.

From issue 2565 of New Scientist magazine, 18 August 2006, page 26

It is, let us remember, a war crime to commit a "grave breach" of the Geneva Convention. Article 8(2)(a)(vi) of the Rome Statute for the International Criminal Court, to which Australia (but not the US) is a party, defines such breaches to include "wilfully depriving a prisoner of war or other protected person of the right of fair and regular trial". The Supreme Court has now declared Hicks to be a person protected by the Geneva Convention, and there must come a point at which Australian law officers who wilfully authorise or approve an unfair and irregular trial of an Australian citizen become complicit in a grave breach of international law.

No doubt Australia's Attorney-General, Philip Ruddock, like the US President, has merely accepted the advice of the US Government lawyers that Guantanamo proceedings were lawful. From now on, that excuse will be unavailing. All the President's lawmen at first advised that Guantanamo was not on American soil, so due process did not apply. That argument was rejected by the Supreme Court in 2004. Next, they advised that the Geneva Convention did not protect the detainees because Afghanistan was a failed state or because they were not wearing military uniforms when captured or because the convention was "quaint" and "obsolete" or because the President as commander-in-chief could override them. Last month, the Supreme Court in the Hamdan case shredded these arguments as well. Were the Bush lawyers abashed? Not at all. One of them, Professor John Yoo, complained: "The court is attempting to suppress creative thinking."

He was one of the "creative thinkers" who approved interrogation techniques such as "waterboarding" (the process that mimics drowning) and "using detainees' individual phobias, such as fear of dogs". Other Bush lawyers approved interrogation techniques ranging from prolonged subjection to cacophonous noise to sexual humiliation and "other scenarios designed to convince the detainee that death is imminent for him and/or so for his family". This was not "torture", they advised, which required pain comparable "to physical injury such as organ failure, impairment of bodily functions or even death".

These "creative" techniques were used at Guantanamo when the base was assumed to be a Geneva-free environment, but the Schlesinger inquiry found that, once taught to military interrogators, they "migrated" with them to Abu Ghraib and other prisons in Iraq, where they were adapted by "sadists on the night shift". It is not clear whether David Hicks has been subjected to them but they have on any view produced an inhumane environment to which no one should be subjected, and certainly not for years on end.

Ruddock believes that Hicks should be tried - but for what, exactly? The US would be entitled to try him for a war crime but so far he has faced only a generalised charge of a conspiracy based on his presence in the ranks of those who fought for the Taliban, which was the de facto government of Afghanistan. It is not a crime to enlist in the army of a government - even a government as unpleasant as the Taliban - otherwise all soldiers on a losing side would be guilty and peace agreements would never be negotiated.

Since the Hamdan decision, Bush lawyers have been back at work drafting legislation for a new tribunal to replace the "special military commissions" - the sad little Star Chambers that were struck down by the Supreme Court. Their early drafts provide no reassurance that these replacement tribunals will secure "the rights of fair and regular trial". A trial cannot be regular if judges and jurors owe obedience to the detaining authority, and the draft legislation provides for trial by US army officers. They cannot be fair with procedures that still prevent the defence from challenging prosecution evidence and admit evidence obtained by torture. At common law, based on Magna Carta, a criminal process cannot be fair if it is delayed through no fault of the defendant for more than five years (the point at which, the Privy Council has held, any death sentence must be commuted). Inevitably, the new tribunal will be subject to Supreme Court challenge, which will take until 2008 to resolve. Hicks and other detainees cannot be faulted for challenging the fairness of the process.

The advent of new forms of terror and new forces to inflict it on the innocent challenges democratic societies to respond with legal processes that do not abandon our cherished values. In some respects, the American record is impressive: internal documents show how strenuously the attempts to evade Geneva protections were opposed internally by US military lawyers. They were denounced by bar associations and defeated - eventually - in the courts and (in the case of torture) by John McCain's work in Congress. But the process is lengthy and unpredictable.

The White House, on present indications, cannot bring itself to grant foreign detainees the "fair and regular trial" by juries in state courts, as afforded to US citizens, nor the court martials afforded to its own soldiers. Nor will it choose an acceptable alternative, such as trial by independent or by international judges.

Given Australia's obligations under the Geneva Convention and the Rome Statute, and the history of demonstrably erroneous advice that the White House has received on interrogation, due process and treatment of foreign prisoners in Guantanamo, it may be time for the Australian Attorney-General to stand up to the Bush lawyers. He could echo the advice of his British counterpart: not only is closure of Guantanamo right in principle, it is right because "the historic tradition of the US as a beacon of freedom, liberty and of justice deserves the removal of what has become a symbol of injustice".

Geoffrey Robertson, QC, is author of Crimes Against Humanity, published this month by Penguin. This is an edited extract from his Kenneth Myer lecture, delivered yesterday at the National Library of Australia.