“A Tree Grows in Brooklyn,” Betty Smith’s 1943 novel, is not often thought of as a spy story, but, in a section three-quarters of the way through, that’s what it becomes—and one with contemporary resonances, at that. It’s 1916, and Francie Nolan, who’s just been laid off from her sweatshop job making artificial flowers, sees an ad for a file clerk: “beginner considered, age sixteen, state religion.” She’s fourteen, but her father has drunk himself to death, and her mother, who supports the family by working as the janitor for three Williamsburg tenement buildings, is nursing a newborn. It’s left to Francie and her younger brother, Neeley, to keep the family going. She answers the ad, lying about her age; a reply comes “on an exciting letter head: a pair of shears lying on a folded newspaper with a pot of paste nearby.” Francie is hired, on trial, by the Model Press Clipping Bureau, on Canal Street, for five dollars a week.

Clipping services were Googles for the mechanical age: paying clients submitted what would now be called search terms, and readers—often young women—would go through periodicals, line by line, looking for mentions of those terms. As Valerie Raleigh Yow notes in “Betty Smith,” her biography of the author, Smith herself worked for such a company, Burrell’s Press Clipping Bureau, when she had to leave school, in circumstances similar to those of her fictional protagonist. In the novel, this is how Smith describes Francie’s first view of the Bureau:

The ten readers sat at long sloping desks. The newspapers of all the states were divided between them. The papers poured into the Bureau every hour of every day from every city in every state of the Union. The girls marked and boxed items sought and put down their total and their own identifying number on the front page.

Francie is put to work memorizing no fewer than two thousand names and headings. (It sounds improbable, but she is a bookish girl, and it was an age of memorization.) After a test, she is given the Oklahoma papers. She’s soon moved up, to Pennsylvania. A printer stamps slips for the items with dates; a cutter slashes them out of the papers with a curved knife (“in spite of the letterhead, there wasn’t a pair of shears on the premises”); the clips and slips are pasted together and mailed out. Another worker collects and bales the remaining newspaper scraps on the floor.

Some of the firm’s revenue comes from actors looking for their names in the press, or from book publishers, or from “seasonal five-dollar author clients” chasing mentions in print for a few months after their books come out. (The economics of the writing profession have never been what they should.) There’s also a very important client who pays out “thousands a year for clippings on the Panama Canal and such.” Unlike those of the slightly older women on the job, who all wear glasses, Francie’s eyes are still good. She’s promoted to reading the city papers.

Then, one day, soon after the United States enters the First World War, “two slow-moving men with heavy feet” come to the Bureau; “one of them pushed his palm under the Boss’ nose and what he saw in that palm made the boss turn pale.” They are there to ask about the Panama Canal client. They set up a stakeout, and, when the client shows up, they seize him. “The client clicked his heels, bowed stiffly and walked out between the two men,” Smith writes. “That evening, Francie told Mama and Neeley how a German spy had been caught right in the office.”

And everything falls apart for the Model Press Clipping Bureau. The government, represented by a man with a briefcase and a lot of forms, asks a lot of questions. The boss is “afraid to take in new accounts no matter how innocent they seem.” There is a rush to cover checks, and most of the staff is laid off. Francie, who is among the last to go, remembers watching as the boss “slashed impotently at newspapers, printed blurry slips and pasted items askew.” Within months, the business has been closed, the office lease broken, the equipment repossessed.

This particular spy may be fictional—though the press, during the First World War, was full of stories about both the hunt for German agents and their supposed interest in controlling American newspapers—but Smith was a good observer of the economics of various opportunities, including those based on intellectual property. (She made it through the Depression working for the Federal Theatre Project, part of the W.P.A.) Her realism about money, and what it means not to have it—to a girl in Williamsburg or to anyone—is one of the reasons that “A Tree Grows in Brooklyn” deserves to be thought of as one of the greatest American novels. (Reading it ought to count as an essential credential for anyone claiming an interest in Williamsburg or Greenpoint, where Smith, anticipating “Girls” by a century, set many of the scenes.) And the espionage interval, fable though it may be, contains some provocative propositions for contemporary versions of the Model Press Clipping Bureau—companies whose business also involves collecting and selling what is, to start with, other people’s information.

One might be to know your customers, and to think about where your revenue is coming from and why. The Panama Canal client was “the backbone” of the Bureau’s business, and so Francie’s boss didn’t ask too many questions. Facebook, in its dealings with certain firms and purported researchers who wanted access to its users’ information, seems to have taken a great deal on faith, as well. This weekend, the Times ran a report on how Amazon and Google might, in the future, enable their voice-activated digital devices to listen and look for activity that might help advertisers tailor messages to a household. Who else might look for such “help,” and what will it cost these companies if users feel that they’ve let a spy into their homes? Facebook has lost billions of dollars in market value already.

At the same time, it’s important to think about the ways that, in a climate of fear, such lessons can be overlearned. Francie notes that, once government agents start showing up, her boss is wary of even the apparently innocent. That could mean being suspicious of the curious, of those who read broadly, or of those interested in connections between events in different parts of the country or the world—perhaps even those organizing protests on matters that have little to do with the war. It is June, 1917, when the Model Press Clipping Bureau closes its doors—the same month that Woodrow Wilson signed the Espionage Act, which was used to lock up people like Eugene V. Debs, who by then had run for President four times as a socialist. (He’s a hero of Bernie Sanders’s.) Some of the worst parts of the act, which criminalized certain speech as “sedition,” were repealed after the war. But it remains a broad piece of legislation that, these days, is most often used to prosecute leakers. Daniel Ellsberg was charged under the Espionage Act, though the case was dismissed due to government misconduct; Chelsea Manning, however, was convicted under the act, and Edward Snowden faces similar charges. In that sense, reading “A Tree Grows in Brooklyn” is a reminder that this very blunt legal tool was forged in a distinct, and distant, cultural and technological context. (Similarly, Snowden’s revelations demonstrated how the government was using legal rationale derived from a case involving old telephone-switch-box technology as justification for collecting cell-phone metadata.) Can the law differentiate between Russian hackers and American dissidents? Would the government, in moments of panic, even want it to?