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

“When I was working on my book, I did an anecdotal survey asking people: Between books, magazines, and newspapers, which do you think has the most fact-checking?” explained Craig Silverman, author of Regret the Error, a book on media accuracy, and founder of a blog by the same name. Almost inevitably, the people Silverman spoke with guessed books.

“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.”

Somaly Mam’s case is far from the first of its kind. In 1999, anthropologist David Stoll questioned the accuracy of I, Rigoberta Menchú, a memoir that describes the horrors experienced by Menchú during Guatemala’s civil war. That same year, Binjamin Wilkomirski, author of the Holocaust memoir Fragments, was revealed not to be a Holocaust survivor at all. And we all watched Oprah poke a million little holes into James Frey’s story of addiction and recovery.

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.”