The war on news leaks by President Barack Obama\'s administration is becoming a threat to press freedom and democracy, a media watchdog group said Thursday. The Committee to Protect Journalists, in a report based on interviews with dozens of news professionals, said the US leader\'s actions sharply contradict his promise of transparency and open government. The report on the United States is unusual for the press freedom group, which has this year completed investigations on Burma, China, Egypt, Iran, Pakistan, and Tanzania. The only time the United States has been the subject of a CPJ report was 19 years ago, in a study on attacks on immigrant journalists. CPJ executive director Joel Simon said the group decided to investigate US press freedom \"because journalists told us that the relationship with the administration had deteriorated to the point where it makes it difficult for them to do their job.\" Former Washington Post executive editor Leonard Downie, author of the report, said he learned that \"administration officials and employees are increasingly afraid to talk to the press\" due to heightened scrutiny of leaks. He said this is in large part due to efforts to prosecute six government employees and two contractors -- including former National Security Agency  contractor Edward Snowden -- under the 1917 Espionage Act. Downie said this was a chilling use of a law, used \"only in three previous cases in the past nine decades.\" Downie, now a professor of journalism at Arizona State University, said Obama has failed to live up to his pledge to make his administration the most transparent in American history. Downie added that the Obama administration\'s \"war on leaks and other efforts to control information are the most aggressive I\'ve seen since the Nixon administration, when I was one of the editors involved in The Washington Post’s investigation of Watergate.\" He said the 30 experienced Washington journalists he interviewed for the report at a variety of news organizations \"could not remember any precedent.\" Downie noted that the policies are also harmful to US efforts to promote press and Internet freedom around the world. Highlighted in the report is the use of the Espionage Act to crack down on news leaks. This was used to prosecute Stephen Jin-Woo Kim, a State Department contract analyst who disclosed information about North Korea\'s nuclear plans to a Fox News reporter. The Espionage Act was also used to prosecute US Army private Chelsea Manning for releasing classified information to Wikileaks. Lucy Dalglish, dean of journalism at the University of Maryland, said the case of Manning, formerly known as Bradley Manning, was a turning point because the law is a powerful tool generally reserved for cases of government spying, not news leaks. \"Prosecution under the 1917 Espionage Act is almost their only tool,\" she said. \"They\'re sending a message. It\'s a strategy.\" White House officials, interviewed for the report, strongly objected being portrayed as against press freedom. \"The idea that people are shutting up and not leaking to reporters is belied by the facts,\" Obama\'s press secretary, Jay Carney, told Downie. But Michael Oreskes, a senior managing editor of The Associated Press, told CPJ that news sources \"are looking over their shoulders,\" due to the stance of the Obama administration. \"Sources are more jittery and more standoffish, not just in national security reporting,\" Oreskes said. \"There\'s a mind-set and approach that holds journalists at a greater distance.\" In a statement accompanying the report, the committee said it was \"disturbed by the pattern of actions\" which \"have chilled the flow of information on issues of great public interest, including matters of national security.\" It said these actions \"thwart a free and open discussion necessary to a democracy\" and called on the Obama administration to \"affirm and guarantee that journalists will not be at legal risk or prosecuted for receiving confidential and/or classified information.\" Christopher Callahan, dean of the Walter Cronkite School of Journalism at ASU, said the mere fact that CPJ chose to investigate the US government\'s treatment of the press \"is a remarkable statement here in the home of the First Amendment.\" \"US government tactics are increasingly impeding journalists\' work and placing a chill on newsgathering that could endanger our democracy,\" Callahan added. In a related development, a group of scholars, journalists, and researchers released an open letter arguing that  mass surveillance is harmful to journalism and incompatible with existing law and policy. “We recognize that electronic surveillance plays a key role in law enforcement and national security,\" said the letter released by the Columbia University Journalism School and the Massachusetts Institute of Technology\'s Center for Civic Media, in a public comment to an intelligence review group set up by Obama. \"However, the tremendous power of Internet-era monitoring raises the most serious kinds of questions about freedom, power and democracy.\"