Welcome to the NewsHour. Meta CEO Mark Zuckerberg took the stand in a Los Angeles federal court today to defend his company and its platform Instagram against allegations it was deliberately designed to be addictive to children and teens.

It's the first time he's testified about child safety in front of a jury. The trial focuses on a now 20-year-old woman,

known by her initials, KGM, who says she became addicted to social media as a young girl,

and that excessive use exacerbated her depression, anxiety, and suicidal thoughts.

At issue is whether tech companies, despite knowing it would cause psychological harm, intentionally

design their social media platforms to hook young users with addictive features like infinite scroll,

personally tailored algorithms, and push notifications.

YouTube is also included in the lawsuit.

TikTok and Snapchat chose to settle before the trial started. The outcome will have

big implications for some 1600 similar cases across the country and could lead to monetary

damages or force major changes to the platforms themselves. For more, we're joined now by

NPR tech correspondent Bobby Allen. Bobby, it's always good to see you.

So what is the central legal question in this case? And what stands out about the strategy

the plaintiffs are pursuing here?

The central question is, are these tech companies legally culpable for hooking young people

to social media apps? And what that essentially will mean

is, will they have to pay billions of dollars in monetary damages? Will they have to make

sweeping reforms to Instagram, to YouTube? And what did they know about the harms to young people?

What did they do to conceal it to the public? And very importantly,

Jeff, was this deliberate? As Omna mentioned, the meta CEO, Mark Zuckerberg, he testified

under oath. What was the atmosphere in the courtroom? You were there. And what did he say?

Yeah, so Zuckerberg took the witness stand, and you could tell he was getting kind of testy.

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