California, Colorado, Kentucky and New Jersey have accused Meta, the parent company of Facebook and Instagram, of deliberately designing its platforms to be addictive to young people and concealing information about potential risks as a landmark trial opened in a US federal court in California.

Opening statements began Tuesday before District Judge Yvonne Gonzalez Rogers in a case expected to last six weeks.

An eight-person jury is serving in an advisory role, with Judge Rogers ultimately responsible for deciding the case.

Megan O’Neill, a deputy California attorney general, told the court that Meta designed its products to “hook the users, hold them for as long as they can, harvest their data, and then hide the truth from the public”.

She said the strategy worked “especially well for kids”.

The four states were among 29 that sued Meta in 2023 over child safety and privacy, with the other 25 cases scheduled for later trials.

The lawsuit accuses Meta of contributing to a youth mental health crisis by knowingly designing features that addict children to its platforms and concealing the resulting harms from the public.

It also alleges that Meta routinely collects data from children under 13 without parental consent, in violation of federal law.

“Meta needed kids, and it needed to reassure the people who cared about those kids that the kids are safe,” O’Neill said.

The four states are seeking billions of dollars in damages and fundamental changes to how Meta operates its platforms.

Meta’s lawyer Paul Schmidt acknowledged that “no dispute” exists that some social media users face struggles, but argued that research shows no clear link between adolescents’ social media use and a lack of wellbeing.

He also said Mark Zuckerberg, Meta’s cofounder and CEO, shares the company’s goal of improving its services rather than making them dangerous.

“They don’t believe they’re going to do well if people don’t like their service,” Schmidt said.

Meta said before the trial that the states’ claims were unsubstantiated and pointed to protections for teenagers, including Instagram Teen Accounts launched in 2024 and a feature allowing parents to set limits on usage.

If Judge Rogers finds Meta liable, she could impose civil penalties and order changes to Facebook and Instagram.

The company could face fines of up to $1.4 trillion, although the coalition is seeking roughly $200 billion.

Meta has already been ordered to pay $942 million in fines in a separate New Mexico lawsuit, including $375 million in civil penalties following a March jury verdict and $567 million ordered by a judge earlier this month.

Meta acknowledged in a January US Securities and Exchange Commission filing that lawsuits it faces, including those concerning youth social media addiction, could result in “substantial monetary damages or fines”.

Stephanie Otway, a Meta spokesperson, told Al Jazeera that the states’ “limited claims are unsubstantiated and their financial demands are vastly disproportionate”.

She said the attorneys general offered “no proof anyone in their states was misled” and were attempting to “penalise Meta” for industry-wide challenges such as age verification.

“Rather than sticking to the facts or the law, the states have instead decided to chase an outlandish payout,” she added.

The first testimony

After opening arguments, former Meta safety engineer Arturo Bejar began testifying as the states’ first witness.

Bejar has long alleged that Meta knew its child safety tools did not work and has testified against the company in four trials.

Meta sought to block his testimony over allegations that he deleted Signal messages with former employees, but Rogers rejected the attempt to exclude the key witness.

Bejar told the court that “move fast and break things” was a mantra at Meta and accused the company of taking a “don’t ask, don’t tell” approach to monitoring whether children under 13 were using its platforms.

“Many products were shipped into the world”, such as Reels short-form videos, “and safety was not a consideration in how it was initially deployed”, Bejar said.

Zuckerberg and Instagram chief Adam Mosseri are also expected to testify.

The case originated with a 2021 US Senate committee hearing in which whistleblower Frances Haugen, a former Facebook data scientist, alleged that the company knowingly promoted products that could affect young users’ health while pursuing higher profits.

Meta has repeatedly sought to end the coalition lawsuit, including through a 2024 effort and a summary judgment request in June.

Al Jazeera’s Eva McKend, reporting from Washington, DC, said the states have a “substantial case”, but that “proving intent” would be their biggest challenge.

She said it “speaks volumes that they were even able to get this far”.

“No doubt, Meta, with all the corporate might that they have, have tried for a long time to get this squashed and not let this reach before a judge,” she added.

A long time coming

The trial has also affected Meta’s stock performance, with shares closing 4.4 percent lower at $543.67 on Tuesday.

The case is the latest in a series of lawsuits against Meta and other social media companies, including Google’s YouTube, TikTok and Snap, alleging that their platforms harm young people, illegally collect their data and are deliberately designed to foster addiction.

As the trial began, child safety advocates and parents who associate their children’s deaths with social media harms gathered outside the courthouse.

Several parents held photographs of their late children while speaking to reporters.

Among those outside the court was Mary Rodee, who said her 15-year-old son Riley Basford died by suicide in 2021 after being victimized by a predator on Facebook.

“They call it spontaneous suicide,” she said. “I call it what it was: the predictable outcome of a system that protects corporations instead of children.”