Xinjiang is the home to the Uyghurs, a Turkic people who mostly follow Islam and have a distinct culture and language. Not surprisingly, the region has a tenuous relationship with Beijing, which is more than 1,400 miles away. Protests, riots and even terrorist attacks have been connected to the Uyghur struggle, which gives cover to Chinese authorities to implement the harshest strategies there.

"Abuses are most apparent in Xinjiang because of the lack of privacy protections but also because the power imbalance between the people there and the police is the greatest in China," said Maya Wang, China researcher at Human Rights Watch.

"The power imbalance between the people there and the police is the greatest in China."

That is why security investment in Xinjiang skyrocketed after the riots. According to Adrian Zenz, a lecturer at the European School of Culture and Theology who has written extensively about the police presence in Xinjiang and Tibet, the region's security forces doubled between 2009 and 2011 to more than 11,000 people. And it kept growing: In 2017, he documented more than 65,000 public job advertisements for security-related positions in Xinjiang, and last year Amnesty International estimated that there were 90,000 security staff in the region, the highest ratio of people to security in any province in China.

Several new tools and tactics accompanied this rise in security personnel, most notably the implementation of "convenience police stations," a dense network of street corner, village or neighborhood police stations designed to keep an eye out everywhere and rapidly respond to any threat, perceived or real. But there were also corresponding investments in security technology on a globally unprecedented scale. It started with a drive to put up security cameras in the aftermath of the 2009 riots before evolving into something far more sophisticated, as Xinjiang turned into a place for state-connected companies to test all of their surveillance innovations.

"The rule of law doesn't exist," said William Nee, China researcher at Amnesty International. "They are able to pioneer new methods of control that, if successful, they could use elsewhere in China."

Today, Xinjiang has both a massive security presence and ubiquitous surveillance technology: facial-recognition cameras; iris and body scanners at checkpoints, gas stations and government facilities; the collection of DNA samples for a massive database; mandatory apps that monitor messages and data flow on Uyghurs' smartphones; drones to monitor the borders. While there's some debate over how advanced the system tying these technologies together is, it's clear that China's plan is for a fully integrated system that uses artificial intelligence to rapidly process massive amounts of information for use by the similarly massive numbers of police in convenience stations.

"[Xinjiang] represents a very new frontier and approach when it comes to online surveillance and oppression."

For Uyghurs, it means that wherever they go, whomever they talk to and even whatever they read online are all being monitored by the Chinese government. According to The New York Times, "When Uighurs buy a kitchen knife, their ID data is etched on the blade as a QR code." BuzzFeed documented stories of family members too scared to speak openly to relatives abroad. And the combination of all of these tools through increasingly powerful AI and data processing means absolute control and little freedom.

"It's one thing to have GPS tracking. It's another thing to monitor social media usage of large populations," said Feldstein. "But to do that in combination with a large DNA database of up to 40 million people and to integrate those methods with other modes of surveillance and intrusion -- that represents a very new frontier and approach when it comes to online surveillance and oppression."

The result, at least for China, is a massive success. Violence in the region has fallen as riots, protests and attacks are now rare in Xinjiang. Part of that is due to the presence of the state, but it's also related to a rise in fear, as no one is sure how pervasive the Chinese surveillance apparatus is.

"People can never be sure if they are free from monitoring," said Nicole Morgret, project coordinator at the Uyghur Human Rights Project. "The fear is such that even if the surveillance is not complete, people behave as if it is. The technology is being rolled out so quickly."

That is because access to the actual platforms being used by the Chinese authorities is limited, and much of the knowledge about surveillance technology comes from observations by the few journalists who can report from Xinjiang or through looking at public tender and budget documents. Or, increasingly, the knowledge comes from observing how other regions in China are being monitored and how Chinese tech companies abroad are deploying or marketing similar tools.