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....

Reducing the visibility of polarizing content in social media feeds can measurably lower partisan animosity. To come up with this finding, my colleagues and I developed a method that let us alter the ranking of people's feeds, previously something only the social media companies could do. Reranking social media feeds to reduce exposure to posts expressing anti-democratic attitudes and partisan animosity affected people's emotions and their views of people with opposing political views. I'm a computer scientist who studies social computing, artificial intelligence and the web. Because only social media platforms can modify their algorithms, we developed and released an open-source web tool that allowed us to rerank the feeds of consenting participants on X, formerly Twitter, in real time. Drawing on social science theory, we used a large language model to identify posts likely to polarize people, such as those advocating political violence or calling for the imprisonment of members of the opposing party. These posts were not removed; they were simply ranked lower, requiring users to scroll further to see them. This reduced the number of those posts users saw....

When Tucker Carlson hosted Nick Fuentes on his show last month, the response followed a familiar script. Critics condemned the platforming of a white nationalist. Defenders invoked free speech. Social media erupted. Fuentes is a 27-year-old livestreamer with openly antisemitic views. He has called Adolf Hitler both 'awesome' and 'right.' But he has become impossible for the Republican Party to banish, despite repeated attempts by some party leaders. This dynamic reveals how fringe ideologies operate differently today compared to the mid-20th century, when institutional gatekeepers ' political parties, law enforcement, the media ' could more effectively contain extremist movements. And through their 21st-century methods of communication and operation, Nick Fuentes and his followers ' the 'Groypers' ' have managed to get what their 20th-century predecessors could not: widespread awareness and political influence. As a historian of the American far right, I have spent years examining how fascist movements adapted to the conditions of postwar America. The trajectory from the 1940s until today shows a fundamental shift: from defined organizational structures that could be dismantled to diffuse cultural movements that spread through social media....

While X is not one of the largest social networks in the U.S., it's still the one to beat within the smaller market of social apps that focus on short, real-time text posts that appear in a vertical feed. This space has seen increased competition since Elon Musk bought Twitter and rebranded it as X in October 2022, as Musk's changes to the platform's content moderation policies and the site's rightward political shift sent some users looking for alternatives. In addition to the growth seen by decentralized, open source networks like Mastodon and Bluesky, other startups launched would-be Twitter rivals like Spill, Post, T2 (Pebble), and Hive. Many of these have since shut down, however. Despite this competition, X hasn't seen much of a slip in usage over the years, according to the report. For instance, Pew's report on U.S. adults' social media use published at the beginning of last year found that X was then used by 22% of U.S. adults. Its 2021 report showed Twitter (before its rebranding to X) was used by 23% of U.S. adults....