Crying “Censorship!” has become the right’s favorite book marketing technique.

Roger Kimball, president of Encounter Books, is the latest publisher to hawk his wares this way in the Wall Street Journal. Last week, on the op-ed page, Kimball complained that Amazon had stopped selling “When Harry Became Sally: Responding to the Transgender Moment,” by social conservative Ryan T. Anderson. Kimball called the move “a deliberate act of censorship” — presumably to placate critics who call the book transphobic. (Amazon founder Jeff Bezos owns The Washington Post.)

Kimball went on to note that “When Harry Became Sally” has also been dropped by Bookshop.org, the indie alternative to Amazon. Far from providing an alternative, “Bookshop,” he claimed, “turns out to be little more than another minion for the Emperor of Wokeness.”

That’s silly, but one point Kimball made draws blood: How can Bookshop defend removing this 2018 book that offends liberal sensibilities while continuing to offer about 20 different editions of Hitler’s “Mein Kampf”?

Bookshop did not respond to a request for comment. But the reason you can buy the Führer’s memoir from a woke online bookseller says a lot about how Web-based merchants function and how they’re changing our relationship to retailers.

Consider that your local indie bookstore contains titles that have been carefully curated according to how much physical space is available, which books the managers consider worthy and what they anticipate customers will want to buy.

The World Wide Web is a different world. Large online book retailers are essentially search engines. They populate their sites by automatically sucking up inventory data from vast wholesalers, such as Ingram, so that they can, in effect, offer every book that exists. In the 1990s, that was part of Amazon’s great innovation, which allowed it to be the World’s Largest Bookstore, despite the fact that it began in Bezos’s garage.

But the convenience of having more than 10 million titles at our fingertips fundamentally changes retailers’ function in ways people don’t often acknowledge or readily understand. There is, it turns out, a price for that infinite inventory. Unlike the cozy bookstore in your town, online booksellers don’t choose each book they’re offering. The role of curator — if it exists at all — has effectively been passed from seller to customer.

Under this system, if a title attracts sufficiently convincing and public objections, that title is taken down from the website. I saw this process firsthand in 2019 when I asked Barnes & Noble why it was selling David Icke’s antisemitic book “The Trigger.” B&N blamed “an independent publishing distributor,” and the book vanished. Earlier this year, I asked Walmart why it was offering the racist “Turner Diaries” on its website; I never got an answer, but the title stopped showing up.

It’s highly unlikely that anyone at Barnes & Noble or Walmart ever looked at these bizarre and hateful books and decided, “Yes, I think our white supremacist customers will love this!” Instead, these books were simply swept up in the retailing equivalent of bottom trawling that drags a net across the ocean floor, catching cod and shrimp along with old barrels of toxic waste.

This feels like a problematic way to curate literature. I don’t want to read antisemitic, racist or transphobic books, but I also don’t want the marketplace of available titles to be shaped by my own or other customers’ objections. If these massive book retailers aren’t really choosing which books to sell except in rare occasions when a few titles are excluded — then perhaps they’ve relinquished their editorial control and become merely administrators of public space, in which case the public may have the right to make certain demands on them.

This issue came up tangentially in a Supreme Court case that had nothing to do with bookselling. In early April, the court declined to rule on whether President Trump could legally block critics from following him on Twitter. The court decided the issue was moot because Trump is no longer in office, but Justice Clarence Thomas appended a statement about the power of big technology companies, and in that statement Thomas offered this warning: “As the distributor of the clear majority of e-books and about half of all physical books, Amazon can impose cataclysmic consequences on authors by, among other things, blocking a listing.”

He went on to suggest that Amazon (along with Twitter, Google and Facebook) may be what’s called a “common carrier,” like a railroad or a telephone network. These older entities don’t choose whose freight or data they carry; if you can pay and you have a legal product, they must take it without discrimination.

Thomas wrote, “There is a fair argument that some digital platforms are sufficiently akin to common carriers or places of accommodation to be regulated in this manner.”

If that’s true — or if the court later decides it’s true — large online booksellers could find themselves in a very different universe. At the moment, Amazon, Bookshop and others are playing two different characters simultaneously: They essentially function as common carriers, offering everything their wholesale databases and distributors can supply. But when a particular book attracts negative attention and offends public sensitivities, these same booksellers act as private businesses and remove that title. The time may be approaching when that clever maneuver is no longer tenable.

April 24 is Independent Bookstore Day, an annual celebration of the essential contributions these literary merchants make to our communities. It’s an occasion to remember that your local bookstore is not just a hopelessly limited version of a glorious Web retailer. No, that bricks-and-mortar shop contains the results of thousands of informed decisions by real people who love literature and chose those books just for you.

Ron Charles writes about books for The Washington Post and hosts TotallyHipVideoBookReview.com.