A mother who is one of a group of British parents suing TikTok after the deaths of their children said she wants "accountability" from the social media firm.
Ellen Roome is in the US for the first day of the hearing, filed by the Social Media Victims Law Centre.
"It’s about time we held them to account and said ‘what are you showing our children?’" she said.
The lawsuit claims her son Julian "Jools" Sweeney, Isaac Kenevan, Archie Battersbee, Noah Gibson, and Maia Walsh all died while attempting a "blackout challenge".
A TikTok spokesperson said: "We strictly prohibit content that promotes or encourages dangerous behaviour."
Subscribe here: http://bit.ly/1rbfUog
For more news, analysis and features visit: www.bbc.com/news
#TikTok #BBCNews