Mr. Musk has built a constellation of like-minded heads of state — including Argentina’s Javier Milei and India’s Narendra Modi — to push his own politics and expand his business empire.

© Cristiana Couceiro

Donald Trump’s social media platform has outdistanced similar conservative sites such as Parler and Gettr, even as it lags far behind X and others.

© John Minchillo/Associated Press

Jackson Hinkle’s incendiary commentary has generated over two million new followers on X since October — a surge that some researchers say is aided by inauthentic accounts.

© Ysa Pérez for The New York Times

China has adopted some of the same misinformation tactics that Russia used ahead of the 2016 election, researchers and government officials say.

© Alice Lagarde