In the landmark antitrust case, tech executives have harked back to a Silicon Valley age when social apps like Facebook, Path, Orkut and Google Plus boomed.

© Annelise Capossela

In her second day on the stand of a landmark antitrust trial over Meta’s power, Ms. Sandberg, the former chief operating officer, also said the company faced plenty of competition from TikTok.

© Jose Luis Magana/Associated Press

President Trump, the Meta chief executive and one of the most aggressive cases the government has ever brought against a big tech company.

© Tom Brenner for The New York Times