US prosecutor James Lewis says the country rushed to warn hundreds of informants after Julian Assange allegedly authoritsed the released of thousands of classified military and diplomatic files.
Some US sources "disappeared" after WikiLeaks' published their real names, Julian Assange's extradition hearing has heard.
Prosecutor James Lewis says the US government rushed to warn hundreds of informants about the publication of thousands of classified military and diplomatic files on the WikiLeaks website in 2010.
At Woolwich Crown Court on Monday, Lewis said some sources in Iraq, Iran, China and Syria were able to evacuate to the safety of third countries.
But the US was unable to contact other sources as it would have put them at even greater risk if they did, and he said: "some people deemed at risk could not be located."
"The United States is aware of sources... who subsequently disappeared," Lewis said.
The prosecutor said it could not be definitively proven they had been harmed or killed.
He spoke of various US adversaries mentioning the classified files after WikiLeaks released them, including the Taliban in an statement to US media.
The prosecution is arguing that the crux of the US case against Assange is that his publishing exposed US sources to risk of harm.
"By disseminating the unredacted materials, he knowingly put people... at risk of serious harm, torture or even death," he told the court.
"What Mr Assange seeks to defend by free speech is not the publication of classified materials, but what he seeks to defend is the publication of the names of sources, the names of people who put themselves at risk, to assist the United States and allies.
"This is the heart of the matter."
Lewis said the names of thousands of sources and at least 150 whistleblowers were exposed by Assange's release of thousands of classified Pentagon and State Department documents.
"The decision to publish was his and his alone," he said.
The hearing is to decide whether Assange, 48, will be extradited to the US to face one charge of conspiring to commit computer intrusion and 17 charges of violating the Espionage Act.
Assange, who was wearing a grey suit and sweater with a white shirt, unexpectedly stood to speak as the judge was about to rise for the lunch break.
"I cannot concentrate and the noise outside is not helpful, even though I appreciate the public support - they must be disgusted with the proceedings," he said, referring to supporters protesting outside.
Earlier Lewis said the Australian is charged with conspiracy to commit computer intrusion for helping former US Army intelligence analyst Chelsea Manning, then called Bradley, hack a password hash so he could hide his identity while accessing and downloading classified files.
Lewis said Assange's assistance to Manning, if successful, could have made it easier for him to hide his identity from US authorities as the source of the leaks.
"These are ordinary criminal charges and any person, journalist or source who hacks or attempts to gain unauthorised access to a secure system or aids and abets others to do so is guilty of computer misuse," Lewis said.
"Reporting or journalism is not an excuse for criminal activities or a licence to break ordinary criminal laws.
"This is true in the UK as it is in the USA, and indeed in any civilised country in the world."
Meanwhile, hundreds of Assange's supporters have called for his freedom as the hearing unfolded.
The Australian's father John Shipton was among the supporters inside the court, while scores of people gathered outside, many chanting "free Julian Assange!"
The protesters carried placards with messages including "Jail the war criminals", "Don't shoot the messenger" and "Don't extradite Assange: Journalism is not a crime".
Speaking to reporters earlier, Shipton criticised "the oppression of journalism (and) the ceaseless malice directed at Julian".
"Today journalism itself is on trial," said the Defend Assange Campaign, which has organised protests on Monday in cities including Berlin, Brussels, Vienna, Athens, New York, Washington, Sydney, Seoul and Mexico City.
Paris-based Reporters sans Frontieres (RSF) also called for Assange's release and said it has sent monitors to the hearing in London.
"It is an unprecedented step for us to undertake this type of international trial-monitoring mission in an established democratic country, which would be more typical in countries ranked much further down our World Press Freedom Index," the head of RSF's London bureau Rebecca Vincent said.
The Council of Europe's human rights commissioner Dunja Mijatovic has also urged Britain not to allow Assange's extradition, saying the case raises important concerns about press freedom and the protection of the rights of whistleblowers.
The UN rapporteur on torture Nils Melzer has found Assange displayed "all the symptoms typical for prolonged exposure to psychological torture" after visiting him in prison in May.
Source: 9News https://www.9news.com.au/national/julian-assange-us-extradition-hearing-uk-court-london-wikileaks-hacking-espionage/4b88921a-4aed-40e9-b819-2fc3c5639081