Here's an excerpt from Ray Bradbury's Fahrenheit 451:

Now let's take up the minorities in our civilization, shall we? Bigger the population, the more minorities. Don't step on the toes of the dog-lovers, the cat-lovers, doctors, lawyers, merchants, chiefs, Mormons, Baptists, Unitarians, second-generation Chinese, Swedes, Italians, Germans, Texans, Brooklynites, Irishmen, people from Oregon or Mexico. The people in this book, this play, this TV serial are not meant to represent any actual painters, cartographers, mechanics anywhere. The bigger your market, Montag, the less you handle controversy, remember that! … Authors, full of evil thoughts, lock up your typewriters. They did. … There you have it, Montag. It didn't come from the Government down. There was no dictum, no declaration, no censorship, to start with, no!

Farhrenheit 451 was published in 1953.

Here's an excerpt from a Washington Post news story:

Before a book is published and released to the public, it's passed through the hands (and eyes) of many people: an author's friends and family, an agent and, of course, an editor. These days, though, a book may get an additional check from an unusual source: a sensitivity reader, a person who, for a nominal fee, will scan the book for racist, sexist or otherwise offensive content. These readers give feedback based on self-ascribed areas of expertise such as "dealing with terminal illness," "racial dynamics in Muslim communities within families" or "transgender issues."… Sensitivity readers have emerged in a climate—fueled in part by social media—in which writers are under increased scrutiny for their portrayals of people from marginalized groups, especially when the author is not a part of that group.

The Washington Post article was published in 2017.

As Post reporter Everdeen Mason points out, if you're an author of best-selling renown whose published works include Harry Potter and the Philosopher's Stone just for starters, you might think you don't need to be screened by a sensitivity reader. You'd be wrong:

Last year, for instance, J.K. Rowling was strongly criticized by Native American readers and scholars for her portrayal of Navajo traditions in the 2016 story "History of Magic in North America." Young-adult author Keira Drake was forced to revise her fantasy novel "The Continent" after an online uproar over its portrayal of people of color and Native backgrounds. More recently, author Veronica Roth—of "Divergent" fame—came under fire for her new novel, "Carve the Mark." In addition to being called racist, the book was criticized for its portrayal of chronic pain in its main character.

Furthermore, sensitivity readers aren't even controversial in the eyes of a surprising number of the media. "What's not to like?" asks Claire Fallon of the Huffington Post:

There's really no meaningful difference between the content editing any reputable publisher would offer and sensitivity reading―except that most agents and editors, to this day, are white, straight, cisgender, able-bodied women. The average editor at a publishing house isn't personally familiar with the experiences of an American bisexual child of Chinese immigrants, or a black teenager, or a deaf woman. An editor can and will alert their author that an odd coincidence reads as ridiculously contrived, or that a character's dialogue seems stiff and unrealistic; that's part of helping a writer hone their craft and polish their book. What, then, if the book's flaw lies in a cultural detail misrepresented, or a glaringly dated stereotype of a person of color? Unless the editor has more fluency in a given culture than the author, the editing process could skip right over that weakness.

And Slate's Katy Waldman, although not quite so enthusiastic about the sensitivity industry as Fallon, still thinks it's a generally good industry to have around:

As a push for diversity in fiction reshapes the publishing landscape, the emergence of sensitivity readers seems almost inevitable. A flowering sense of social conscience, not to mention a strong market incentive, is elevating stories that richly reflect the variety of human experience. America—specifically young America—is currently more diverse than ever. As writers attempt to reflect these realities in their fiction, they often must step outside of their intimate knowledge. And in a cultural climate newly attuned to the complexities of representation, many authors face anxiety at the prospect of backlash, especially when social media leaves both book sales and literary reputations more vulnerable than ever to criticism. Enter the sensitivity reader: one more line of defense against writers' tone-deaf, unthinking mistakes.

Even authors these days seem to see no problem in having to rewrite their books to fit the exquisite sensitivities of sensitivity readers. Waldman mentions one author "who totaled 12 sensitivity reads for her second novel on LGBTQ, black, Korean American, anxiety, obesity, and Jewish representation issues, among others."

There's another name for sensitivity screening, of course. It's called self-censorship. In Fahrenheit 451 some 64 years ago, Ray Bradbury prophesied that ever-increasing authorial sensitivity to the demands of an ever-increasing group of aggrieved minorities would result in books so blandly inoffensive that no one would care about books anymore. And then you'd have actual censorship.