Undercover techniques date back to the early 1900s  and questions about the ethics of this approach have been debated for almost as long. The likes of Hunter S. Thompson and Elizabeth Jane Cochrane (writing as Nellie Bly) are two of the most legendary names in undercover journalism . Their respective reports from inside the Hell’s Angels and from behind the walls of an insane asylum are enduring examples of the power of undercover techniques and the lengths journalist go to get the story.
Undercover remains a popular tool in the journalist’s arsenal; examples are prevalent on television programs like the fifth estate and CBC’s Marketplace, as well as in stories published by various print and online platforms in Canada. As Brooke Kroeger explains in her book Undercover Reporting: The Truth About Deception, the practice of undercover journalism predates television and has only become more effective and popular with the advent of the Internet, which allows the nuance of undercover work to be shared through multimedia . The diversity of undercover work is vast; Kroeger’s work outlines 33 different approaches, which are only some of the possibilities . According to Kroeger, undercover tactics can include instances where journalists become customers or clients, cold-call sources, avoid correcting mistaken impressions, and gain access with incomplete or misleading information .
Despite the diversity of the work itself, the ethical debates around undercover work are relatively simple: the technique conflicts quite starkly with journalists’ moral duty to tell the truth. Greg Marx describes the complaints arising from undercover tactics as “ready-made” saying, “If the reporter has forfeited the high ground of transparency and honesty, how can his conclusions be trusted by the public?” 
Robert Osborne, a reporter and producer with decades of undercover experience and an instructor at Ryerson University suggests the techniques be used only when the story is important enough to warrant such lengths and only ever when all other options have been exhausted.
“It’s a very intrusive form of journalism, undercover. You are taking things from people without asking – that’s the very nature of it. You’re taking their picture, you’re recording their audio – whatever you’re doing you are taking from them without asking. So that’s a pretty extreme form of research and reporting,” says Osborne .
For these reasons there is widespread caution among journalists to use the tactics selectively and only when necessary. A three-step test is set out in The Elements of Journalism (2014) to determine whether a story meets the threshold for undercover work, including (1) whether the information is vital to the public interest, (2) there is no other way to get the story and (3) the deception is disclosed to the audience .
 Kroeger, Brooke. Undercover Reporting: An American Tradition. Investigative Reporters and Editors Inc. 2014. 32 (2).
 Kroeger, Brooke. Undercover Reporting: The Truth About Deception. 2012
 Marx, Greg. The Ethics of Undercover Journalism. Columbia Journalism Review. 2010.
 Robert Osborne. Interview done by Brittany Spencer. 2016.
 Kovach, Bill & Tom Rosenstiel. The Elements of Journalism. 2014.