Journalist Nellie Bly went undercover
Very few news organizations practice major investigative journalism on subjects that matter, even though there's an honorable history of uncovering stories using deception, such as Nellie Bly pretending to be insane in 1887 to reveal hideous abuses in a New York lunatic asylum.
In 2007, reporter Ken Silverstein went undercover as a representative of an energy company with business interests in a repressive country. He contacted Washington lobbyists, who told him for the right fee (up to $1.5 million a year) they would send congressional delegations to visit the place, write and plant opinion pieces in newspapers, and create "independent" media events to promote the country.
After his article exposing these events was published in Harper's Magazine, there was criticism leveled... at Silverstein. Some charged him with being unethical by deceiving the lobbyists.
Their Men in Washington - The Harper's Magazine article exposing the lobbyists
Undercover, under fire - Silverstein's response to critics of his deception, from the Los Angeles Times>>
Deception/Hidden Cameras Checklist, an journalism ethics checklist by Bob Steele, from The Poynter Institute>>