Burstien hoped that Psy-Group’s work in Tulare would help the company land other small campaigns, but that proved overly optimistic. He told colleagues that he was close to finalizing several deals, but the new clients fell through, and, in February, 2018, Burstien found that he couldn’t make payroll.

Psy-Group’s financial woes coincided with sudden scrutiny from the F.B.I. The Bureau had taken an interest in George Nader for helping to organize a secretive meeting in the Seychelles ahead of Trump’s Inauguration, with the aim of creating an unofficial channel with Vladimir Putin. In January, 2018, F.B.I. agents stopped Nader, an American citizen, at Dulles International Airport and served him with a grand-jury subpoena. Nader agreed to coöperate, and told F.B.I. agents about his various dealings related to the Trump campaign, including his discussions with Zamel. (Nader has been granted immunity in exchange for testifying truthfully, according to one of his representatives. “Someone who has this kind of immunity has no incentive to lie,” the representative said.)

The following month, F.B.I. agents served Zamel with a grand-jury subpoena. Agents also tracked down Burstien in the San Francisco area, where he was on a business trip. Burstien returned to his hotel room and found a note under his door informing him that the Bureau wanted him to come in for questioning. Burstien told friends that he was “in shock.” The F.B.I. also visited Psy-Group’s so-called D.C. office, at the WeWork, and seized a laptop computer that had been hidden in a desk drawer, where it had been running continuously.

The F.B.I. questioned some of Burstien’s employees about Psy-Group’s activities. In the interviews, agents acted as if “there’s no smoke without fire,” a former company official said. “There was a lot of smoke,” the official acknowledged. “We had to show them, it’s smoke, it’s smoke, it’s smoke, and not fire.” Psy-Group officials referred the F.B.I. to the letters they had received from law firms, attesting to the legality of their activities and telling the company that it didn’t need to register as a foreign agent. “The F.B.I. seemed genuinely surprised that this shit wasn’t illegal,” a former Psy-Group employee said.

In an interview, Burstien said that he was comfortable with how Psy-Group had operated but believed that changes were needed to protect average citizens. “I’m coming from the side of the influencer, who really understands how we can make use of online platforms,” he said. “There needs to be more regulation, and it’s up to our legislators, in each and every country. What have U.S. legislators done since they learned, more than two years ago, about the potential of these new capabilities? They have the power to move the needle from A to B. Nothing substantial has been done, as far as I know.”

Ram Ben-Barak, who helped woo Benzeevi on behalf of Psy-Group, said that he decided to leave the company after he learned about the extent of its operations in Tulare, which he objected to. Ben-Barak said that he regrets his decision to work with the firm. “When you leave the government and you leave Mossad, you don’t know how the real world works,” he said. “I made a mistake.” Ben-Barak, who is now running for a seat in Israel’s parliament, said that he believes new regulations are needed to stem the proliferation of avatars and misinformation. “This is the challenge of our time,” he said. “Everything is fake. It’s unbelievable.”

Gadi Aviran, the Terrogence founder, said that he “never dreamed” that the business of fake personae, which he helped establish, would become so powerful. “In order to understand where we are, we have to understand where we started,” he said. “What started as a noble cause ended up as fake news. What you have today is a flooded market, with people that will, basically, do anything.”

In Tulare, the test of Psy-Group’s strategy came on the night of July 11, 2017. The hospital-board election resulted in a landslide—but not for Psy-Group’s client. There were more than a thousand ballots cast, and only a hundred and ninety-five people voted for Kumar to keep his seat. Senovia Gutiérrez won with seventy-five per cent of the vote. In the end, the Web sites attacking Senovia attracted scant attention in the community. “It was like they organized a concert and nobody showed up,” a computer-security expert said after reviewing trace data from the sites, which were taken down after the election.

After Senovia’s victory, Benzeevi’s contract was rescinded. Larry Blitz, a hospital-turnaround specialist, stepped in as the interim C.E.O., and discovered that the hospital’s financial records were completely disorganized, with “entries that indicated artificial means of balancing the books.” Eventually, Blitz said, his team realized that the accounts contained a “hole as big as the Grand Canyon.” The hospital was more than thirty-six million dollars in debt, and had to close for nearly a year. (It reopened in October, 2018.) One morning, Blitz’s chief financial officer found police carting away computers and telephones. The local district attorney has issued more than forty search warrants as part of a fraud investigation, one of the largest such investigations in Tulare County history. Benzeevi and his legal team refused to respond to questions about Psy-Group. At first, Kumar said that he wasn’t aware of the covert campaign and that he wanted to help with this story. Then he stopped returning calls.

According to a former company official, Zamel decided to shut down Psy-Group in February, 2018, just as Mueller’s team began questioning employees. But its demise hasn’t suppressed the appetite for many of the services it provided. Some of Psy-Group’s former employees have met with Black Cube to discuss job opportunities. Black Cube has been criticized for some of its recent work, including for the producer Harvey Weinstein, but there’s no sign that the notoriety has hurt business; one person familiar with the company’s operations bragged that there was booming interest from a variety of corporations. Recently, Efraim Halevy, who served as the director of Mossad from 1998 to 2002, joined Black Cube’s advisory board. Uzi Arad, a Mossad veteran and a former national-security adviser for Netanyahu, said that he was ashamed to see some of his former colleagues become “mercenaries for hire,” adding, “It’s highly immoral, and they should know it.”

Last year, Black Cube moved to one of Tel Aviv’s most expensive neighborhoods, where it now occupies a sleek, full-floor office in the Bank Discount Tower. The entrance is unmarked, and painted black; doors are controlled by fingerprint readers. One area of the office is decorated with spy memorabilia, including an old encryption machine.

Some Psy-Group veterans expressed regret that the firm had closed. “Had the company still been open, all this so-called negative press would have brought us lots of clients,” one said. Despite embarrassing missteps, which have exposed some Psy-Group and Black Cube operations to public scrutiny, a former senior Israeli intelligence official said that global demand for “private Mossads” is growing, and that the market for influence operations is expanding into new commercial areas. In particular, the former official cites the potentially huge market for using avatars to influence real-estate prices—by creating the illusion that bidders are offering more money for a property, for example, or by spreading rumors about the presence of toxic chemicals to scare off competition. “From a free-market point of view, it’s scary,” a former Psy-Group official said, adding that the list of possible applications for avatars was “endless.” Another veteran of Israeli private intelligence warned, “We are looking at the tip of the iceberg in terms of where this can go.” ♦