That was in 2009. This past spring, Simon Marks’s Newsweek article on Mam charged the anti-sex trafficking activist with fabricating her past as a child prostitute. In the fallout, many readers faulted Kristof for lauding her as a heroine; others pointed fingers directly at Mam. Hardly any called out the publishing houses that distributed her book.

Mam’s story gained a mass following with the release of her best-selling memoir, first published in France in 2005. The book’s success helped the activist launch the Somaly Mam Foundation in 2007. Mam was also featured in Mariane Pearl’s In Search of Hope that same year.

In a Politico post, Kristof cited the fact that Mam’s story had been the subject of two published books as part of what made it so credible. Addressing the issue in the Times, he wrote, “We journalists often rely to a considerable extent on people to tell the truth, especially when they have written unchallenged autobiographies.”

There’s a basic problem with this line of logic, though: Most books are never fact-checked.

“A lot of readers have the perception that when something arrives as a book, it’s gone through a more rigorous fact-checking process than a magazine or a newspaper or a website, and that’s simply not that case,” Silverman said. He attributes this in part to the physical nature of a book: Its ink and weight imbue it with a sense of significance unlike that of other mediums.

Fact-checking dates back to the founding of Time in 1923, and has a strong tradition at places like Mother Jones and The New Yorker. (The Atlantic checks every article in print.) But it’s becoming less and less common even in the magazine world. Silverman suggests this is in part due to the Internet and the drive for quick content production. “Fact-checkers don’t increase content production,” he said. “Arguably, they slow it.”

What many readers don’t realize is that fact-checking has never been standard practice in the book-publishing world at all.

And reliance on books creates a weak link in the chain of media accuracy, says Scott Rosenberg, founder of the now defunct MediaBugs.org. “Magazine fact-checkers typically treat reference to a fact in a published book as confirmation of the fact,” Rosenberg said, “yet too often, the books themselves have undergone no such rigorous process.”

These cases vary widely but share that they have many unfortunate effects. Critics of Menchú’s political views were quick to completely discredit a rare survivor testimony. Conservative commentator David Horowitz labeled her a “Marxist terrorist” and “one of the greatest hoaxes of the 20th century” before launching an unsuccessful campaign to revoke her Nobel Peace Prize. Wilkomirski’s downfall fanned the flames of Holocaust denial.

Kristof urged readers not to let Mam’s falsehoods overshadow her cause.

“One risk is that girls fleeing Cambodian brothels will no longer get help,” he wrote in a Times blog post. “… Let’s remember that this is about more than one woman.”

Why then, with the perils so apparent, are so many books still not fact-checked?

The reluctance may stem in part from a sense that it’s unkind to question victims, especially when their pasts portray them unfavorably. Nan Talese, Frey’s editor, sat beside him on the couch at Oprah. “As an editor,” Talese wondered, “do you ask someone, ‘Are you really as bad as you are?’”

Or perhaps people are too in love with resilience narratives—the more harrowing Frey’s original circumstances, the more buoyed we felt by his success.

Publishing houses cite lack of funds for fact-checking operations, but it’s getting harder to accept that argument, particularly with major presses. Even when a line-by-line, magazine-style edit is unrealistic, publishers could work to clear certain key details. In Frey’s case, for example, Doubleday might have verified court records, as The Smoking Gun was able to do, regarding the amount of time he spent in jail (a few hours, instead of months).

And publishers often find funds for an in-depth legal vetting process, during which lawyers carefully review a manuscript and flag any passages that may expose the author or publisher to issues of legal liability. These issues may fall into the categories of copyright and fair use, right of privacy, right of publicity, and defamation, explains Tonya M. Evans, a law professor at Widener University and author of a series of legal reference guides for publishing professionals. “The goal is to raise these issues so that the client can make an informed decision whether it is in their best interest to publish the work as is or make changes, secure permissions, or delete certain material altogether,” Evans says.

Some authors are taking matters into their own hands. When Mac McClelland, formerly a fact-checker at Mother Jones, wrote her first book, For Us Surrender Is Out of the Question: A Story from Burma’s Never-Ending War, she enlisted the help of former MJ research editor Leigh Ferrara to pore through more than 700 sources. The process took about eight months. 

McClelland recently finished fact-checking her second book, Irritable Hearts, a memoir about her experience of PTSD as a reporter covering conflicts and disasters. Because this work is more personal than her last, much of the checking this time around consisted of questions for McClelland’s family, exes, and friends.

“Everything you remember, somebody else remembers it differently,” McClelland said. “Everything I would ask each of my parents, the other one would say, ‘The complete opposite of that happened.’” She caught statistical and historical inaccuracies before publishing her first book; with her second, she changed some personal stories, too.

Scott Rosenberg of MediaBugs agrees. “I just think you’d have to rip up the publishing industry as it exists and start over if you really wanted publishers to fact-check books,” he said. Publishers aren’t motivated to take on this vast responsibility, he believes, without commercial pressure.

“They don’t pay a price when the book is exposed,” Rosenberg pointed out. “No one looks at the publishing house’s name on the book they bought four years ago when Newsweek exposes it as inaccurate and says, ‘I’ll never buy a book published by them again!’ So why should the publisher care?”

Even in the case of A Million Little Pieces, for which Random House was made to offer refunds as part of a federal class-action lawsuit, the financial repercussions were minimal. Of the more than four million readers who purchased the book, fewer than 2,000 sought refunds. Random House set aside $2.35 million for the lawsuit, but even with legal fees, wound up paying far less.

Perhaps in a perfect world, every publishing house would have an army of fact-checkers—but what can we do until then? At the very least, it’s important to read more critically, especially for journalists, who perpetuate untruths when they rely blindly on books for fact.

“Maybe there should be a warning, like on a pack of cigarettes,” said McClelland. “‘This book has not been fact-checked at all.’ Because when I realized that basically everything I had read until that point had not been verified, I felt a little bit lied to.”