US senators on Wednesday grilled the biggest social media and messaging companies, saying they had failed to do enough to protect children from sexual predators on their platforms, and said Congress must quickly pass legislation.

The hearing marks the latest effort by lawmakers to address the concerns of parents and mental health experts that social media companies put profits over making sure their platforms do not harm children.

“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,” said Senator Lindsey Graham, referring to Meta CEO Mark Zuckerberg. “You have a product that’s killing people.”

Zuckerberg testified along with X CEO Linda Yaccarino, Snap CEO Evan Spiegel, TikTok CEO Shou Zi Chew and Discord CEO Jason Citron.

Senator Dick Durbin, the Judiciary Committee’s Democratic chairman, cited statistics from the National Center for Missing and Exploited Children nonprofit group that showed financial “sextortion,” in which a predator tricks a minor into sending explicit photos and videos, had skyrocketed last year.

“This disturbing growth in child sexual exploitation is driven by one thing: changes in technology,” Durbin said during the hearing.

As the hearing kicked off, the committee played a video in which children spoke about being victimised on the social media platforms.

“I was sexually exploited on Facebook,” said one child in the video, who appeared in shadow.

In the hearing room, dozens of parents had stood waiting for the CEOs to enter, holding pictures of their children.

X’s Yaccarino said the company supported the STOP CSAM Act, legislation introduced by Durbin that seeks to hold tech companies accountable for child sexual abuse material and would allow victims to sue tech platforms and app stores.

The bill is one of several aimed at addressing child safety. None have become law.

X, formerly Twitter, has come under heavy criticism since Elon Musk bought the platform and loosened moderation policies. This week, the company blocked searches for pop singer Taylor Swift after fake sexually explicit images of Swift spread on the platform.

Wednesday also marked the first appearance by TikTok CEO Chew before U.S. lawmakers since March when the Chinese-owned short video app company faced harsh questions, including some suggesting the app was damaging children’s mental health.

“We make careful product design choices to help make our app inhospitable to those seeking to harm teens,” Chew said, adding TikTok’s community guidelines strictly prohibit anything that puts “teenagers at risk of exploitation or other harm — and we vigorously enforce them.”

Chew disclosed more than 170 million Americans used TikTok monthly — 20 million more than the company said last year.

Under questioning by Graham, he said TikTok would spend more than $2 billion on trust and safety efforts, but declined to say how the figure compared to the company’s overall revenue.

Senator Ted Cruz grilled Zuckerberg about warning screens on Instagram that alerted users an image might show child sexual abuse, but still allowed them to see the image.

“Mr. Zuckerberg, what the hell were you thinking?” Cruz said.

Zuckerberg responded that it can be helpful to redirect users to resources rather than blocking content, adding the company would follow up with more information about the notice.

He reiterated earlier in the hearing that the company had no plans to move forward with a previous idea to create a kids version of Instagram.

Senator Amy Klobuchar on Wednesday questioned what she said was inaction in the tech industry, comparing it to the response shown when a panel blew out of a Boeing plane earlier this month.

“When a Boeing plane lost a door in flight several weeks ago, nobody questioned the decision to ground a fleet. … So why aren’t we taking the same type of decisive action on the danger of these platforms when we know these kids are dying?” Klobuchar said.