China exploits how search engines work to influence public opinion outside the country, by landing state-published stories about the detention of Uyghur Muslims and the origins of the coronavirus at the top of Google, YouTube and Bing searches. 

In a report published Friday, researchers at the Brookings Institution and the Alliance for Securing Democracy found that Chinese sources consistently land at the top of search results for "Xinjiang," a part of western China made up of the Uyghur minority. 

When Brookings compiled daily data over 120 days, 12 terms related to Xinjiang returned state-backed content in the first 10 results in 88% of searches on Google Search and News, Bing Search and News, and YouTube. Some of that content whitewashed China's forced assimilation of Uyghurs, which the US State Department has called crimes against humanity. 

Searches for Fort Detrick, a military base in Maryland that was the center of the US' biological weapons program from the early 1940s to the late 1960s, return a high volume of Chinese propaganda that promotes conspiracy narratives about the facility being the actual source of coronavirus outbreak, according to the report. On YouTube, the report finds, searches on Fort Detrick "regularly returned state-backed content, with 619 observations of videos from Chinese state media outlets appearing in the top 10."

Google Search and YouTube are banned in China. Microsoft's Bing operates in China but suspends some elements of the service to comply with the country's laws.

China's search engine strategy indicates that it's willing to use Western tools to influence audiences outside the country. The report says the tactic dovetails with the tough language of China's "wolf warrior" diplomats, who use brusque language to push the country's talking points. China's search tactics aim to "assert narrative dominance" through "external propaganda aimed at foreign audiences," according to the report.

"The issue is that Chinese state media, which isn't really beholden to resource constraints or audience feedback, can churn out a large volume of propaganda on a conspiracy it wants to promote," said Jessica Brandt, a Brookings researcher who studies authoritarian governments and the internet. The high volume of material makes it easier for Chinese publishers to take advantage of the way search works to promote fresh content, Brandt said.

Ned Adriance, policy communications manager at Google, said the search giant tries to "combat coordinated influence and censorship operations" while balancing free expression. Some search queries used in the study were less common terms, which may explain why Chinese state sources were in top results, Google said.

Microsoft, which recently fixed a bug that applied some Chinese political censorship to search in North America, said it was reviewing the report.