Australia is actually doing this. As of December 10, no one under 16 will be allowed to have an account on TikTok, Snapchat, YouTube, Instagram, or basically any other platform an average teen might care about. Other countries have attempted partial restrictions, but Australia’s Online Safety Amendment is the first real ban, and it comes with heavy fines for social-media companies that fail to comply. “Social media was a big social experiment,” says Julie Inman Grant, Australia’s eSafety commissioner, who is in charge of enforcing the law. “In some ways, this is an antidote social experiment.”

The inspiration came from Annabel West, who is married to Peter Malinauskas, South Australia’s premier (roughly the equivalent of a governor). Last year, she read The Anxious Generation: How the Great Rewiring of Childhood Is Causing an Epidemic of Mental Illness, a best seller by Jonathan Haidt, arguing that among teens, a spike in anxiety, depression, self-harm, and eating disorders coincided with the wide distribution of cellphones. Australia has a history of sudden, sweeping social reforms. In 1996, shortly after the Port Arthur massacre, in Tasmania, the country introduced dramatic restrictions on firearms. Malinauskas drafted the social-media legislation for South Australia, and within a year, the Online Safety Amendment passed as national law.

The law somewhat vaguely requires social-media companies to take “reasonable steps” to stop kids under 16 from having or creating accounts on their platforms. The social-media companies initially responded predictably, Inman Grant told us, saying they couldn’t possibly comply and that they had no idea who was actually under 16. But Inman Grant, an American who worked for 20 years in Big Tech, rolls her eyes at most of their excuses and is determined to push them to do better.