Annie McGrath never had to worry too much about her 13-year-old son Griffin. He had good grades and lots of friends.

Griffin played baseball and the drums and had even won a national science competition. Because he was so interested in science and experiments, he spent a lot of time watching YouTube videos. That's where he and his friends saw something called the blackout challenge.

"We had heard of challenges," said McGrath, who lives in Madison, Wis. "But I never knew there were any that were deadly."

Social media challenges involve people recording themselves doing something dramatic, funny or risky. The videos often go viral. Some of these dares, however, can be dangerous. Like the blackout challenge, which is when someone holds their breath until they pass out.

That's what happened to Griffin one night in February 2018. He did the blackout challenge from his room, while FaceTiming with friends. Only he never woke up.

"I didn't know anything was wrong until it was too late," McGrath said, in an exclusive interview with NPR.

On Friday, she addressed YouTube's parent company Alphabet during an annual shareholder meeting calling for change and accountability.

Griffin is one of an estimated 1,385 people known to have died from the blackout challenge, according to a nonprofit called Erik's Cause, which was founded by Judy Rogg, whose son also died from a choking game. Tracking these numbers can be difficult. "Formal statistics are limited because no public health databases monitor these activities," states the nonprofit.

"That's just the tip of the iceberg," McGrath said. "The only ones we know of are the people that go to the news or find each other."

YouTube spokesperson Brittany Stagnaro told NPR that the company's policy is to remove videos that involve challenges with asphyxiation or choking. But, McGrath said she sees such videos and reports them daily. Often they're not taken down. She said some videos have remained on the site for years.

Pressuring those with a financial stake: shareholders

McGrath, along with an advocacy group called Parents Together, is now pressuring the people who have a financial stake in YouTube to get the company to have more transparency around its protocols for these videos.

On Friday, McGrath urged Alphabet shareholders to vote for Resolution 15, which was filed by socially responsible investment firm Harrington Investments and advocacy group Ekō. This resolution proposed a third-party review of Alphabet's Audit Committee, which is tasked with assessing risk to the company, including how YouTube manages videos with harmful content.

In her speech, McGrath said Alphabet's "inaction" on these videos "should give investors pause" and that it demonstrates the company isn't appropriately avoiding legal risk, regulatory risk and human risk.

Glass Lewis, a leading proxy adviser in this space, also backed the resolution. It shared its report with NPR, which said an independent evaluation of Alphabet's Audit Committee could benefit shareholders.

The giant tech company, however, recommended investors vote against Resolution 15. In its opposing statement, it said that its Audit Committee has the "requisite experience, skill set, and protocols" to manage risk and that the resolution wouldn't be an "effective use of company resources or result in better direction or performance."

During the meeting on Friday, Alphabet's assistant secretary Kathryn Hall told McGrath "we are truly sorry for your loss" and that "keeping kids safe online is incredibly important to us." She said YouTube has removed millions of videos that violate its policies; and then she restated the company's opposing statement to the resolution.

McGrath's speech at the meeting was one of the first times a family member of a victim told their personal story at a shareholder event, said Zak Rogoff, who studies shareholder resolutions as a research manager for the nonprofit Ranking Digital Rights.

"The thing that's interesting about this is that shareholders have brought somebody who is personally affected by the problems the company is causing," Rogoff said.

Alphabet's shareholders ended up voting against Resolution 15.

Rogoff said these outside resolutions rarely pass because the shareholder voting structure typically gives more weight to votes from people who run the companies. "But if they get a high enough amount of support, sometimes companies will start to budge just out of caution," he said.

Parents try multiple pressure tactics to keep kids safe

Speaking to shareholders is just one of many tactics parents are now taking to keep kids safer online. McGrath and dozens more parents who say their kids have also died from other things they've seen on social media, like suicide from bullying, disordered eating and drug use, have formed a group.

The parents are approaching the issue from all sides to put pressure on both lawmakers and the tech companies. They're in a class-action lawsuit against YouTube and TikTok and they've been lobbying Congress.

The pressure is working.

Last week, the U.S. Surgeon General issued a first-of-its-kind guidance saying social media can have a "profound risk" on the well-being of children and teens. And in the past six months, there's been a slew of bills introduced at the federal and state levels aimed at keeping kids safe online.

"It's low-hanging fruit for bipartisan support," said Zeve Sanderson, executive director of New York University's Center for Social Media and Politics. He said there's something visceral about hearing the stories of children who've been harmed and people can relate to it. "There's been a lot of appetite for policies that focus on social media."

For McGrath, she just wants to make sure no more kids are able to find a blackout challenge video.

"They're still kids and they're going to think, oh, well, they see it a bunch on YouTube and it's not scary, it's normalized," McGrath said. "It just breaks my heart over and over and over again. These are preventable deaths."