Secretary of Defense Robert M. Gates said Sunday that an announcement by the Taliban that they were going through classified military dispatches from Afghanistan posted by the website WikiLeaks 'basically proves the point' that the disclosures put at risk the lives of Afghans who had aided American forces. 'Growing up in the intelligence business, protecting your sources is sacrosanct,' said Gates, a former director of the CIA. He said that while it was up to the Justice Department to investigate who supplied the documents to the website, run by Julian Assange, an Australian activist who is an outspoken opponent of American and NATO involvement in Afghanistan, he had been 'mortified, appalled' at Assange's willingness to make public documents that listed the names of individual Afghans. 'There's also a moral culpability,' he told Christiane Amanpour, in her debut as the host of ABC's 'This Week.' 'And that's where I think the verdict is guilty on WikiLeaks. They have put this out without any regard whatsoever for the consequences.' Sen. Carl Levin, D-Mich., who heads the Armed Services Committee, said on CNN's 'State of the Union' that the Pentagon was assessing the disclosure's impact on operational security in Afghanistan. 'There quite clearly was damage,' Levin said. The New York Times, The Guardian in London and Der Spiegel in Germany published excerpts of the leaked documents, but excluded those that identified individuals or compromised operations. At the request of American officials, The Times also urged WikiLeaks not to post any documents that would put individual sources in jeopardy. As the authorities continued their investigation into the source of the leaks, a Seattle-based software developer who has volunteered for WikiLeaks said he was detained at Newark International Airport on Thursday and questioned for three hours. The developer, Jacob Appelbaum, 27, said in an interview that as he was returning from an overseas trip, agents from Immigration and Customs Enforcement and from the Army's criminal investigation division asked him about Assange. Officials from Immigration and Customs Enforcement, part of the Department of Homeland Security, would not comment. Appelbaum's account came as Gates and the chairman of the joint chiefs of staff, Adm. Mike Mullen, renewed their condemnation of the leak. Both noted that the Taliban had announced they were reviewing the website for names of those who helped the United States. Appelbaum said he had been a volunteer for WikiLeaks for several months, but was not involved in reviewing information submitted to it. Investigators, however, appear to be examining whether Assange was assisted by others in obtaining the documents. 