When a San Diego-based mother posted an emergency alert on Nextdoor, a community discussion app, she hoped a Good Samaritan could help, according to court filings. Her son was hysterical after losing a flash drive with his homework near the local McDonald’s, she wrote, uploading a photo along with the message. A neighbor quickly replied, explaining that the chewing-gum-sized object in the picture was not a flash drive: It was a Juul vaping device.

“That’s just an indication of how quickly Juuls became prevalent,” recounted Esfand Nafisi, a lawyer who is handling two of three lawsuits initiated against Juul Labs last month. “You blinked your eye, and suddenly they were all over the place.”

This has become a new kind of reality for those with children who Juul, the verb used by fans of Juul Labs’ trendy USB-flash-drive-sized e-cigarette. The San Francisco-based company, which launched in June 2015, grew sevenfold this year, according to a study published by Tobacco Control.

Juul Labs has claimed its product is for adult smokers only, but several lawsuits contradict that mission. The filings allege the start-up deceptively marketed the Juul as safe and targeted youth from the get-go. Juul Labs spokeswoman Victoria Davis told The Post in an email that company officials “do not believe the cases have merit and will be defending them vigorously.” But researchers say that Juul’s sly age-verification technique and social media marketing campaigns are most revealing of the company’s true intent.

One of Nafisi’s cases against Juul is a nationwide class action. The 10 named plaintiffs, who range from 14 years old to adult users living in several states, allege that Juul caused nicotine addiction in consumers. According to court documents, the Juul device is “more potent than a cigarette,” allowing high levels of nicotine to enter the bloodstream at a faster speed than cigarettes.

“How much nicotine is the Juul actually delivering into the bloodstream of an average person?” Nafisi asked. “If it’s far more than a cigarette, we believe that’s information that ought to have been disclosed but was not.”

The class action also alleges that Juul’s advertising campaigns, primarily through social media, targeted youths under the legal smoking age. So does another suit filed in a New York federal court last month by attorney Jason Solotaroff on behalf of a soon-to-be high school sophomore identified only as D.P.

The 15-year-old tech aficionado, a jazz player and track star, began attending a new high school where Juuling was rampant. It was “on the school bus, in the bathrooms, outside school and even in class,” according to court documents. Solotaroff told The Washington Post that it didn’t take much time before the boy was hooked and grew intensely addicted.

Juul currently controls 68 percent of the electronic cigarette market in the United States, where it offers Juul pods that contain 5 percent nicotine, far higher than the 1.7 percent legal limit in Britain or Europe. In early 2018, Juul entered the international market, launching in Israel, which has no age restriction on the advertising or selling of e-cigs to minors. The company also hit United Kingdom shelves three weeks ago, after developing Juul pods that complied with the European Union Tobacco Products Directive.

Despite public health concerns and increased scrutiny from the Food and Drug Administration that have led to bans by local governments, the Wall Street Journal reported that the start-up raised $650 million in funding earlier this month, valuing the firm at $15 billion — a figure well beyond the $1 billion valuation required to be dubbed a Silicon Valley unicorn.

Juul Labs has since sidestepped several other obstacles:

Anecdotal accounts of teens sporting Juuls at school and reports of use among minors have sparked broadsides against the product. Local governments, including in California and New York, have voted to ban flavored nicotine products. Members of Congress have called for additional oversight. State lawmakers have launched investigations into the start-up’s practices. And China’s trade war may draw additional blows for the vaping device.

CEO Kevin Burns has stayed calm, assuring the Wall Street Journal that the company remains committed to eliminating cigarette smoking by providing adult smokers with an effective alternative. But snowballing doubts loom around the sincerity of the Juul mission statement: to improve the lives of the world’s 1 billion adult smokers.

“I think Juul has been insincere from the very beginning in saying it’s only for adult smokers,” said Robert Jackler, principal investigator at a Stanford University School of Medicine program that studies the impact of tobacco advertising. He noted that Juul Labs executives have boasted that they run “the most educated company, the most diligent, the most well-researched.”

According to Jackler, the company developed a stealthy email technique that attaches to its screening process. To access and sign up for Juul, the website requests all visitors’ birthdays and the last four digits of a social security number. If the person is not old enough, the site denies access, yet it nevertheless adds the visitor to Juul’s email list-serve, he said. The underage rejected visitor begins receiving promotional campaigns for new fruity flavors and large discounts off the $49.99 starter kit.

A spokesperson from the company denied engaging in the practice: “If a person fails the age verification process, he or she does not get added to an email list-serve to receive information and additionally would be unable to purchase product from us. JUUL is intended for adult smokers only. We cannot be more emphatic on this point: no minor or non-nicotine user should ever use JUUL.”

Most smokers, according to the Centers for Disease and Control Prevention, are over 25 and taper off by midlife.

“If you were designing an ad campaign to hit that target audience, Juul’s is misaligned,” Jackler told The Post. The Stanford program that researches tobacco ads has studied the company’s advertising, marketing and promotion, including early content that has been scrubbed since its June 2015 unveiling, according to Jackler. “There’s an ample amount of evidence that Juul launched with a promotional campaign aimed entirely at younger users and spent its first six months establishing themselves in the youth market.”

The sweet flavors have a differential appeal to youth.

“If you walk down the cereal aisle in the grocery store, where the Cocoa Krispies and Sugar Puffs are at knee level and Cornflakes and Life are up high where adults see them, there’s a different appeal of sweet and fruity flavors to young people,” Jackler said.

Although the company recently announced plans to offer Juul pods with lowered nicotine levels of 3 percent, it intends to make them only in tobacco and mint, flavors that the conventional cigarette and menthol smoker would most likely purchase. The options attractive to younger users — fruit medley, crème brûlée, mango, cool cucumber — remain at 5 percent.

Lynn Kozlowski, former dean of University of Buffalo’s School of Public Health and Health Professions, told The Washington Post that it is important to discourage tobacco use and make clear the risks of nicotine use.

“It shouldn’t be suggested that these products are safe, but they’re nowhere near as dangerous as cigarettes,” he said. “If a kid who otherwise would have been a cigarette smoker becomes a Juul smoker, that’s arguably a good thing for public health.”

But is it?

Juuls could certainly be used as a tool to stop smoking cigarettes. However, Jackler stressed, Juul exploits the business model of addiction.

Most smoking-cessation programs — such as patches and gums — are meant to be used for short stints as smokers wean themselves off tobacco. Juul, however, wants its users to transition from combustible tobacco to Juul and then sustain the addiction.

As research and development engineer Ari Atkins said before the product’s 2015 launch, according to The Verge: “We don’t think a lot about addiction here because we’re not trying to design a cessation product at all.”

Read more:

FDA cracks down on sales of Juul, other e-cigarettes to youths

The Juul’s so cool, kids smoke it in school

He started vaping as a teen and now says habit is ‘impossible to let go’