Silicon Valley is reeling from the seismic verdict delivered by an LA jury on Wednesday. Tech giants Meta and YouTube were found to be liable for designing their platforms to be addictive, which harmed a 20-year-old's mental health.

The plaintiff at the heart of the case was only known by her first name Kaley, and after nine days of deliberation, the jurors agreed with her on all counts. Some in the tech world have sought to downplay this case's impact, while others fear it's the beginning of a public reckoning that poses a threat – potentially an existential one – to US social media companies.

As one insider who asked not to be identified told the BBC, we're having a moment.

The view from inside Meta

The verdict has forced those inside the companies to grapple with the fact that many outsiders do not view them as favourably as they have come to view themselves. That realisation has been difficult for companies that a decade ago were hailed as critical to connecting and entertaining people, and even helping to spread democracy around the world.

Meta, and YouTube owner Google, have both said they will appeal the jury's verdict, which included $3 million (£2.3 million) in compensation and an additional $3 million in damages intended to punish the companies.

Kaley claimed the platforms amplified her personal issues and left her with body dysmorphia, depression, and suicidal thoughts. It was a clean sweep with respect to liability against both Google and Meta, case attorney Jayne Conroy told the BBC after the verdict. It will matter.

As the companies face an onslaught of liability claims, evidence and testimony heard in Kaley's case could be recalled in upcoming trials. The trial's outcome could set a precedent for future cases that test whether social media companies can be held liable for their product designs.