"[10] He has written stories on a many subjects including in the past decades on BP, Enron, the California Energy Crisis, the Bush administration's torture policies, and the Plame affair.
He has also written about foreign and domestic policy online for publications such as The Guardian,[11] Alternet, CounterPunch, Common Dreams, The Huffington Post, Political Affairs Magazine, The Raw Story, Scoop, ZNet and others.
[18][19][20] Leopold was referred to as "one of the most aggressive reporters" on the California energy crisis by Jill Stewart, a columnist for the now-defunct New Times LA newspaper in Los Angeles.
"[25] Leopold later admitted that he had been careless by not providing the FT with additional credit, but insisted that Salon's editors had all the relevant documents, including the disputed White email, before the story was published.
[25] Paul Krugman of The New York Times, who wrote a piece based in part on Leopold's work, also had to backpedal, acknowledging that he should not have cited the e-mail.
[25][27] The Village Voice reported, "Obviously, Leopold made mistakes, but it's not at all clear they justify a full repudiation of the story or a revocation of his journalistic license.
'"[27] Commenting on the case, Kerry Lauerman of Salon said that "Leopold definitely represents the dark side of the web ... he became this sort of hero for throngs of people online".
The Post wrote that it was canceled following reported legal threats from Steven Maviglio, the press secretary to former Governor Gray Davis, who, according to the manuscript, invested in energy companies using inside information.
[17] In the book, Leopold also revealed many secrets about his life such as a prior drug addiction, bouts with mental illness and suicide attempts.
[17] Publishers Weekly wrote of News Junkie that "While there's a lot of lying admitted to in this scrappy memoir, from Leopold's hiding of his criminal past to his playing of sources to get his scoops, it's (probably) not an untruthful memoir—indeed, it might become required reading for aspiring journalists.
[33] Truthout vigorously defended the story saying variously that it had two or three "independent sources", before the executive director, Marc Ash, issued a statement apologizing for “getting too far out in front of the news-cycle”.
[38] CNN's Randi Kaye in an article also cited a report by Leopold on Mark Kovak's inside knowledge about the safety concerns at the Prudhoe Bay, Alaska BP oil field.
[40] On July 14, 2010, the United States House of Representatives Committee on Transportation and Infrastructure held a hearing in the Subcommittee on Railroads, Pipelines and Hazardous Materials.
[43] The Air Force removed the material from its training regime a day after Leopold's story was published, with David Smith, chief of public affairs of Air Education and Training Command, telling Leopold (The material) "has been taken out of the curriculum and is being reviewed," and "The commander reviewed it and decided we needed to have a good hard look at it and make sure it reflected views of modern society.
"[44] In 2010 Leopold and psychologist and human rights worker Jeffrey Kaye requested information on the use of psycho-active drugs on Guantanamo captives.
[50] He is the journalist whose Freedom of Information Act lawsuit forced the State Department to release all of Hillary Clinton's emails on a monthly basis.
[49] On 18 January 2019, Leopold co-authored an explosive report that alleged Donald Trump directed his personal lawyer Michael D. Cohen to lie to Congress about the Moscow tower project,[51] a construction deal at the heart of an investigation by the special counsel Robert S. Mueller III.
[54] The Washington Post opined that Michael Cohen's testimony to the House Oversight Committee largely confirmed the thrust of the report but contradicted key details.