Social media bosses including Mark Zuckerberg were told they had "blood on your hands" when they appeared before a committee of US Senators on Wednesday.
The boss of Meta, which operates Facebook and Instagram, appeared alongside the chief executives of influential social media platforms among young people, including X, TikTok, Snap and Discord, to face questions on their efforts to combat online child sexual exploitation.
The hearing began with a video in which children spoke about being victimised on the social platforms, with one child saying: "I was sexually exploited on Facebook."
Senator Lindsey Graham told the Facebook entrepreneur: "Mr Zuckerberg, you and the companies before us, I know you don't mean it to be so, but you have blood on your hands.
"You have a product that's killing people."
Mr Zuckerberg went on to apologise to families who held up pictures of their children who they said had been harmed by social media.
Asked by Senator Josh Hawley if he wanted to apologise, Mr Zuckerberg stood up, turned around, and addressed the families.
"I'm sorry for everything you have all been through. No one should go through the things that your families have suffered and this is why we invest so much and we are going to continue doing industry-wide efforts to make sure no one has to go through the things your families have had to suffer," he said.
Committee chairman Senator Dick Durbin quoted statistics from the National Center for Missing and Exploited Children non-profit group, showing showed financial "sextortion", in which a predator tricks a minor into sending explicit photos and videos, skyrocketed last year.
"This disturbing growth in child sexual exploitation is driven by one thing: changes in technology," Mr Durbin said during the hearing.
TikTok CEO Shou Zi Chew said the firm would spend more than two billion US dollars on trust and safety efforts, but declined to say how the figure compared to the company's overall revenue.
Mr Zuckerberg said Meta was "committed to protecting young people from abuse on our services" but described it as "an ongoing challenge".
He added: "As we improve defenses in one area, criminals shift their tactics, and we have to come up with new responses."
Mr Zuckerberg reiterated that the company has no plans to move forward with a previous idea to create a kids version of Instagram.