Tech giant Meta is partly responsible for the alleged murder of an NYC teen, whose killer relentlessly harassed her online before her death, her devastated dad said in a $50 million lawsuit.

The alleged killer, a 15-year-old unsupervised foster kid, launched a month-long cyberbullying campaign against Emery Lynn Mizell, 17, via Meta Platforms-owned Instagram, which has “actively concealed” the dangers of the platform, the victim’s father, Tony Mizell, claimed.

The culmination of the harassment came on May 2, 2024 when the 15-year-old girl fatally stabbed her in the chest as she walked home from school in Soundview, according to the Bronx Supreme Court case.

“This tragedy was entirely preventable,” Mizell said in court papers, which also blames the city Administration for Children’s Services, which he claims did nothing to discipline the unhinged teen or lift a finger to intervene.

The lawsuit, first filed in March and moved this week into Manhattan Federal Court, comes weeks after a California jury dished out a $6 million verdict against Meta and found the company liable for one young woman’s social media addiction.

“The cyberbullying campaign that preceded and precipitated Emery’s murder was conducted
through Instagram, a platform that Defendant Meta Platforms, Inc. has deliberately designed to be
addictive to teenagers,” Mizell argued in the lawsuit.

Instagram’s algorithms boost “harmful and inflammatory” content, while the app helps “create compulsive checking behavior” and creates “addictive feedback loops,” according to the lawsuit.

“Meta failed to adequately warn users, parents, and the public about the known dangers of Instagram, including its addictive nature and its facilitation of bullying and harassment among teenage users,” the dad said in the lawsuit.

The suspect and the victim had not met in person, and only had contact via social media, said Mizell, who marked the second anniversary of her death last week with a balloon release and dozens of the girl’s friends.

“My daughter told the girl to just leave her alone, ‘I don’t want any problems with you,’ but the girl kept going,” he told The Post. “They didn’t know each other.”

Meta “has long known, facilitates and amplifies bullying and harassment among its youngest users,” according to court papers.

The aspiring nursing student’s brutal slaying was “a direct and proximate result” of Meta’s negligence — and ACS’s failure to monitor and intervene with their seriously troubled young charge, the dad alleged.

ACS “should have known” the suspect, identified in the legal filing only as RH, had “violent propensities and history of aggressive behavior,” and failed to protect the public or intervene “despite clear warning signs of escalating violence,” he alleged in the lawsuit.

“This case is about accountability, holding the defendants — particularly Meta — accountable so this doesn’t happen to other children in this city, state and country,” said attorney Sanford Rubenstein, who reps Mizell alongside lawyer Mark David Shirian. “What this father hopes is that it will prevent other deaths by calling attention to it.”

“There is evidence to show there was zero to little oversight over these children. It raises questions about what’s going on in this agency,” Shirian added of ACS.

Emery, the oldest of four kids, was a month away from graduating Metropolitan Soundview High School when she was killed.

Her 15-year-old sister Gianna now sleeps each night in the living room, to be near her slain sister’s cremated remains which are kept in a memorial at their home, Mizell said.

“My world’s totally upside down,” he said.

“It’s a parents worst nightmare. I’m scared for my other daughter. I’ve not slept in the last two years.” 

Meta claimed it has strict company policies against bullying, harassment and threats, and regularly removes such content. In January 2024, Meta also began limiting teens to the strictest messaging settings, so they could only get messages from those they know, the company said.

“ACS is committed to providing the highest quality care and support to children and youth in our care. We are currently reviewing this lawsuit with the Law Department,” an ACS spokesperson said.