Sun Yaoning monitored Tsai Ing-wen's Southern California visit itinerary and reported back to the Chinese Communist Party
In April 2023, during Tsai Ing-wen's visit to Southern California, Sun Yaoning reported her whereabouts in real time to officials at the Chinese consulate in Los Angeles; the U.S. Department of Justice called him a secret agent of China, and he was later sentenced to 48 months in prison.