The lawsuit, filed in 2024 by Attorney General Andrea Campbell, alleges that Meta did this to make a profit and its actions affected hundreds of thousands of teenagers in Massachusetts who use the social media platforms.
"We are making claims based only on the tools that Meta has developed because its own research shows they encourage addiction to the platform in a variety of ways," said state solicitor David Kravitz.
Kravitz added the state's claim has nothing to do with the company's algorithms or failure to moderate content.
Meta said it strongly disagrees with the allegations and is "confident the evidence will show our longstanding commitment to supporting young people."
Meta lawyer, Mark Mosier, argued in court that the lawsuit "would impose liabilities for performing traditional publishing functions" and that its actions are protected by the First Amendment.
"The commonwealth would have a better chance of getting around the First Amendment if they alleged that the speech was false or fraudulent," Mosier said. "But when they acknowledge that its truthful that brings it in the heart of the First Amendment."
Several of the judges, though, seem to more concerned about Meta's functions such as notifications than the content on its platforms.
"I didn't understand the claims to be that Meta is relaying false information vis-a-vis the notifications but that it has created an algorithm of incessant notifications ... designed so as to feed into the fear of missing out, fomo, that teenagers generally have," Justice Dalila Wendland said. "That is the basis of the claim."
Justice Scott Kafker challenged the notion that this was all about a choose to publish certain information by Meta.
"It's not how to publish but how to attract you to the information," he said.
"It's about how to attract the eyeballs. It's indifferent the content, right. It doesn't care if it's Thomas Paine's 'Common Sense' or nonsense. It's totally focused on getting you to look at it."
Meta is facing federal and state lawsuits claiming it knowingly designed features - such as constant notifications and the ability to scroll endlessly - that addict children.
In 2023, 33 states filed a joint lawsuit against the tech giant claiming that Meta routinely collects data on children under 13 without their parents' consent, in violation of federal law.
In addition, states including Massachusetts filed their own lawsuits in state courts over addictive features and other harms to children.
Newspaper reports, first by The Wall Street Journal in the fall of 2021, found Meta knew about the harms Instagram can cause teenagers - especially teen girls - when it comes to mental health and body image issues.
One internal study cited 13.5 per cent of teen girls saying Instagram makes thoughts of suicide worse and 17 per cent of teen girls saying it makes eating disorders worse.
Critics say Meta hasn't done enough to address concerns about teen safety and mental health on its platforms.
A report from former employee and whistleblower Arturo Bejar and four nonprofit groups this year said Meta has chosen not to take "real steps" to address safety concerns, "opting instead for splashy headlines about new tools for parents and Instagram Teen Accounts for underage users."
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