It is an ambitious social experiment of our moment in history — one that experts say could accomplish something that parents, schools and other governments have attempted with varying degrees of success: keeping kids off social media until they turn 16.

One of the world's toughest social-media crackdowns took a week to become law, after a lawmaker's wife read Jonathan Haidt.

Critics say big questions remain not only about how the new law will be enforced, but also about whether the ban will really protect young people.