Chinese espionage in California
The government of the People's Republic of China and entities affiliated with the Chinese Communist Party have undertaken influence operations, political intelligence gathering, cyber espionage, and industrial espionage in California. The state faces "the most mature" Ministry of State Security networks of any in the United States. Activities in California are reported to be coordinated by the MSS 18th Bureau, which was established around 2010 to manage operations across the United States. Espionage activities are especially common in the San Francisco Bay Area. The Chinese government's effort is long-term; they try to recruit politicians early in their career so that if they advance to the national level, that politician will be primed to advocate for Chinese government interests.
Organization
According to sinologist Alex Joske, "California was a treasured staging ground for political influence operations and economic espionage. Its extensive united front networks, clusters of advanced technology and undeniable electoral heft make it prime territory for MSS officers. Today, the state holds the honour of having an MSS unit dedicated to influence and intelligence work in it." Silicon Valley is home to multiple united front organizations linked to the PRC government's system of technology transfer.Activities
San Francisco, with its nearby Silicon Valley, political importance in the Democratic Party, and large contingent of Chinese immigrants, is the centerpiece of operations in California for the MSS. According to US intelligence officials contacted by Politico, "if California is elevated among Chinese interests, San Francisco is like nirvana to the MSS, because of the potential to target community leaders and local politicians who may later become mayors, governors or congressmen." Several suspected MSS officers have been identified operating out of the San Francisco consulate.Cyber espionage
In June 2021, the Metropolitan Water District of Southern California, among other organizations, was reported to have been targeted in cyber espionage hacks by a Chinese state-backed advanced persistent threat. In July 2021, a federal grand jury in San Diego indicted four Chinese nationals working with the Hainan State Security Department under the hacking group APT40 who were alleged to conduct a cyber espionage campaign from 2011 to 2018. In March 2024, the United States and United Kingdom jointly indicted and sanctioned members of the Hubei State Security Department for a wide range of cyber operations against critical infrastructure in the two countries, including attacks on a California managed service provider.In July 2025, the operator of most of California's electric grid, the California Independent System Operator, was reported to have been breached by Chinese state-sponsored hackers due to a zero-day vulnerability in SharePoint which also affected numerous other organizations.
Military-related espionage
In March 2008, an engineer for L3 Technologies in California, Chi Mak, was sentenced to 24 years for conspiring to send defense technology to China.In June 2008, Xiaodong Sheldon Meng, an engineer based in Cupertino, was convicted under the Economic Espionage Act of 1996 and sentenced to two years in federal prison for attempting to sell fighter-pilot training software to the People's Liberation Army Navy.
In February 2010, a former Boeing and Rockwell International engineer in Southern California, Dongfan "Greg" Chung was sentenced to 15 years in federal prison for espionage and other charges related passing technology secrets, including from the Space Shuttle program, to China.
In September 2020, a former University of Southern California professor, Hao Zhang, was sentenced to 18 months in federal prison for conspiring to steal and sell smartphone signal technology to the Chinese military.
In August 2023, a former U.S. Navy sailor assigned to the USS Essex in San Diego, Jinchao Wei, was indicted under the Espionage Act of 1917 for passing videos, photos, and manuals of naval weapon systems to a Chinese intelligence officer. In August 2025, Wei was convicted. He was sentenced to more than 16 years in prison.
In January 2024, a former U.S. Navy sailor, Wenheng Zhao, was sentenced in federal court in Southern California to two years for transmitting details about U.S. military operations to a Chinese intelligence officer in exchange for bribes.
In December 2024, federal authorities arrested and charged a Chinese national, Yinpiao Zhou, for clandestinely flying a drone over Vandenberg Space Force Base to take photographs.
In July 2025, the United States Department of Justice charged two Chinese nationals, Yuance Chen and Liren "Ryan" Lai, with attempting to recruit U.S. military personnel and gather naval intelligence for China's Ministry of State Security. According to the Federal Bureau of Investigation, Lai, who had ties to an MSS network, began cultivating Chen—then a legal U.S. resident—in 2021 due to his military contacts. The two met with MSS agents abroad and coordinated espionage efforts, including the use of a dead drop in 2022, where they left $10,000 in cash in a California locker to pay individuals for intelligence. Chen later toured the USS Abraham Lincoln in San Diego and collected personal details of Navy personnel, which were allegedly passed to Lai. The Justice Department stated that the operation was part of a broader Chinese effort to expand its “blue-water” naval capabilities and undermine U.S. national security. Both men were charged under the Foreign Agent Registration Act, which requires individuals acting on behalf of foreign governments to register with U.S. authorities.
In July 2025, a former engineer at a South California company, Chenguang Gong, pleaded guilty to stealing military tracking blueprints for the Chinese government.