also through a high-ranking informant. As soon as he became aware of new details, he shared the Klan's secrets with police, prosecutors, journalists, and human rights organizations. In 1947, after a year of working undercover, he consented to testify in a trial against the leaders of the Columbians, Homer Loomis and Emory Burke, who were found guilty. Kennedy claimed that in 1946, he provided information – including secret codewords and details of Klan rituals – to the writers of the Superman radio program, intending to strip away the Klan's mystique. There was a series of 16 episodes in which Superman took on the Klan. Kennedy claimed that the trivialization of the Klan's rituals and codewords likely had a negative impact on Klan recruiting and membership. This led Stephen J. Dubner and Steven Levitt to dub Kennedy "the greatest single contributor to the weakening of the Ku Klux Klan" in their 2005 book Freakonomics. In 2006, Dubner and Levitt cast doubt on their claim with correction that "the story of Stetson Kennedy was one long series of anecdotes — which, no matter how many times they were cited over the decades, were nearly all generated by the same self-interested source". Critical assessments from his peers In 1999, freelance historian Ben Green alleged that Kennedy falsified or misrepresented portions of The Klan Unmasked. During the 1990s, Green had enlisted Kennedy's help while researching a book about the still unsolved murders of Florida couple Harry and Harriette Moore, black Civil Rights activists who died of injuries from the bombing of their home on Christmas Eve 1951. Green's book about the Moores, Before His Time, was published in 1999. Green, whose book is generally disparaging of Kennedy, claimed to have examined Kennedy's archives at the Schomburg Center for Research in Black Culture in Harlem and Atlanta and he concluded that a number of interviews, portrayed in I Rode With The Ku Klux Klan as having been conducted undercover, had in fact been done openly, and that racist material amassed by Kennedy had also been openly obtained from mail subscriptions to the Klan and similar groups and not surreptitiously, as Kennedy implied. Most seriously, Green accused Kennedy of concealing the existence of a collaborator, referred to as "John Brown" (a pseudonym presumably chosen in honor of the 19th-century abolitionist John Brown). This pseudonymous collaborator, Green alleged, was in fact responsible for the most daring of