TikTok Is Gripped by the Violence and Misinformation of Ukraine War

Bre Hernandez used to scan TikTok for videos of makeup tutorials and taco truck reviews. Since Russia invaded Ukraine, the 19-year-old has spent hours each day scrolling the app for war videos, watching graphic footage of Ukrainian tanks firing on Russian troops and civilians running away from enemy gunfire.

“What I see on TikTok is more real, more authentic than other social media,” said Ms. Hernandez, a student in Los Angeles. “I feel like I see what people there are seeing.”

But what Ms. Hernandez was actually viewing and hearing in...