Efforts to reach Mr. Borker at the time were unsuccessful, although he was not keeping a particularly low profile. Earlier in the year, he posted a GoFundMe plea for $1,000 to buy long skis for an April trip to Utah. His short skis, he said, would not suffice in deep-powder snow.

“Clearly, I don’t want to pay for this upgrade,” he wrote, in what by his standards qualified as a charm offensive. “Please give me money.”

The government’s complaint also states that Mr. Borker recently posted a photo collage on his Facebook page showing him atop an enormous pile of eyeglasses. Next to the photos was what sounded like a job posting.

“I am looking for a responsible fast paced person who can assist me at my Brighton Beach office doing various projects for my eye wear e-Commerce business,” he wrote. “Project one will be to help me sort this mess.”

Mr. Borker, a 41-year-old immigrant from Ukraine, stands about 6 feet 5 inches tall. In 2010, when he was terrifying customers of DecorMyEye, which was based in Brooklyn, there was a method to his noxious technique: He believed that Google’s search algorithm could not distinguish between positive and negative feedback. The more people griped about his company, his theory went, the more prominently his site appeared in Google search results.

“I’ve exploited this opportunity because it works,” he told a reporter for The New York Times who visited his home in the Sheepshead Bay section of Brooklyn. “No matter where they post their negative comments, it helps my return on investment. So I decided, why not use that negativity to my advantage?”

In essence, Mr. Borker believed that the internet allowed him to turn upside down long-cherished verities of commerce, most notably that treating customers well enhances one’s bottom line. Using aliases such as Stanley Bolds and Tony Russo, he threatened to chop off the legs of one customer. He threatened to rape another. He wrote a letter to the office of yet another in which he said the customer was gay and sold drugs.