Is China building a voice database to identify its citizens?

China is already known for its extensive internet surveillance but now the country seems to be going a step further, into biometrics. According to official tender documents and police reports gathered by Human Rights Watch, they are collecting voice patterns of individual citizens. This is suspected to be part of a wider effort to establish “large scale biometric databases,” and the voice patterns will be linked with other personal information that the police already has on file–such as personal address and hotel records.

Construction of the national voice database reportedly began in 2012, and the Anhui province was identified as being one of the pilot regions for this initiative. (The government has reportedly partnered with iFlytek to build the database–a voice recognition company based in the province). Anhui police issued an order to speed up the construction two years later, according to police documents. In 2015, the region supposedly saw 70,000 collections of voice patterns.

Human Rights Watch contends that there is no clear official justification for why the government is taking this step. Scientists have stated that it will help with criminal investigations. There has been evidence that the police are using it for this purpose, but there is also evidence that they’re collecting voice patterns of ordinary citizens, such as domestic migrants and passport applicants from the Xinjiang region.

China is not alone in its biometrics push: The faces of more than 125 million Americans—more than half of the country’s adult population—are thought to be stored in a vast network of databases used by local and federal law enforcement, and Congress has been asking why.