In 2007, investigative journalist Ken Silverstein went undercover to test Washington lobbyists’ taste for sleaze. Using an alias, Silverstein created a fictitious energy firm that ostensibly did business in Turkmenistan and approached professional lobbyists to see if they could help cleanse the regime’s neo-Stalinist reputation. The bill for services rendered—newspaper op-eds bylined by established think-tankers and academics, visits to Turkmenistan by congressional delegations, and other exercises in public relations—would have been about $1.5 million. (Disclosure: I consider Silverstein a friend.)

But when Silverstein’s piece, “Their Men in Washington: Undercover With DC’s Lobbyists for Hire,” was published in the July issue of Harper’s, the resulting uproar had less to do with craven lobbyists than with journalistic impropriety. Various critics assailed Silverstein for his charade: Washington Post media reporter Howard Kurtz, an ethics expert at the Poynter Institute, a CBS News blogger, an American Journalism Review writer, and other notables. Journalists shall not lie, the critics mainly agreed. Doing so diminishes their credibility and that of the entire profession.

But Silverstein’s subterfuge was no outlier, as Brooke Kroeger demonstrates in her comprehensive history and exercise in soul-searching, Undercover Reporting: The Truth About Deception. For more than 150 years, American journalists have been playing make-believe to get themselves thrown into jails and loony bins; conniving their way into punishing factory jobs; and posing as high school students, Ku Klux Klan members, and even pregnant women in search of abortionists.

Journalists have even fashioned Mission: Impossible scenarios to snare wrongdoers, as the Chicago Sun-Times did in 1978, when it acquired a downtown bar, named it The Mirage, and staffed it with reporters. The paper documented, in a 25-part series, payoffs to city health inspectors, shakedowns by state liquor inspectors, tax fraud, kickbacks, and other crimes. The series was regarded as both a sensation and an abomination—although a Pulitzer Prize jury tapped it for an award in the Local Investigative Specialized Reporting category, the Pulitzer board overturned the jury’s selection because it disapproved of the Sun-Times’s methods.

Kroeger approaches the genre as a fan and champion. Her goal, largely accomplished with this book, is to polish undercover’s tarnished image and restore it to the place of respect (or semi-respect) it once enjoyed. Kroeger aims to establish undercover reporting as a common technique, not just the work of a few rogue reporters—and to convince journalists that it ought to be used more often.

Her restoration project does not suffer for raw material. A reporter for Horace Greeley’s New York Tribune used a variety of cloaking strategies while covering the American South just before the Civil War, including lying to sources about where he was from and changing “names, places, and dates” in his dispatches to avoid detection. In 1887, New York World reporter Nellie Bly became famous for impersonating a lunatic to gain admittance to a madhouse so she could report on its awful conditions. Between the 1960s and the 1990s, Kroeger writes, a variety of mainstream newspapers exposed housing discrimination by having black and white reporters pose as home buyers or prospective tenants. Gloria Steinem’s scored a cultural expos√© in the early 1960s when she used her grandmother’s name and Social Security number to get a job as a Playboy bunny and wrote about it for Show magazine. In 1992, ABC News exposed substandard meat-handling practices at Food Lion, but told a raft of lies to get its reporters inside as employees.

Kroeger’s point with all this historical research is to put undercover reporting on a continuum, from no-lie investigations on one end to Mirage-style theatrics on the other. But she gives what I consider to be an over-expansive definition of undercover reporting. Almost any project that has relied on any combination of deception and subterfuge to expose a story of public importance seems to qualify. For instance, her lead example is the 2007 Washington Post series by Anne Hull and Dana Priest about the deplorable treatment of patients at Walter Reed Army Medical Center. As Kroeger acknowledges, Hull and Priest never assumed false identities in their reporting. They told no lies and donned no disguises. Yes, they shunned personnel who might ask them nosy questions, and they didn’t ask officials for permission to report at the hospital. But if such evasive maneuvers equal “undercover reporting,” I would hypothesize that 75 percent of all working reporters have at one time or another in their career gone “undercover,” too.

Jack Shafer writes a column about the press and politics for Reuters.