Imagine having to rename your children so that they would not be targeted by the police. Imagine being afraid to pray in public. Imagine being forced to download an app that warns you to delete “dangerous” photos on your phone. All of this, against the constant threat of being sent to political “re-education” camps.

This may sound like an Orwellian nightmare, but it is the daily life for millions of people living in Xinjiang, an autonomous region in western China. This large region—the size of Texas, California, Nevada, and Minnesota combined—is home to one of the greatest human rights catastrophes occurring today, with massive implications for the right to free expression.

Xinjiang has been marked by tensions between the Chinese government and the region’s major ethnic groups, most notably the Uyghurs, a Turkic, Muslim-majority group that comprises about half of the region’s population. In the name of combating “Islamic extremism,” the Chinese Communist Party (CCP) has turned Xinjiang into a police state, where those who publicly express their ethnic identity are marked as potential enemies of the state. Observers have declared that in Xinjiang “Big Brother meets Big Data,” with unimaginable consequences for millions.

Those the CCP deems to be “infected” with radical Islamic ideology are seized and sent off to political “re-education camps” for “deradicalization.” According to one set of estimates, up to a million Uyghurs are believed to be detained. Even more conservative estimates place hundreds of thousands of Uyghurs and other ethnic groups such as the Kazaks, the Hui, among others, in these political indoctrination camps. Those detained are not given a trial, a lawyer, or any semblance of due process. Even more shocking, Uyghurs and others are sent to the camps for everyday expressions of their culture or faith. Uyghurs have been detained for making pilgrimages to Mecca, growing a beard, and even quoting the Quran.

While within these camps, detainees are subject to political indoctrination and abuse. Some detainees have been force-fed pork—a meat forbidden to be eaten by Muslims—as punishment. Other detainees who did not recite the political indoctrination lessons taught in these camps were not allowed to eat, sit, or sleep.

Policing, both visible and invisible, is a daily presence in Xinjiang. Police officers routinely check citizens’ phones for banned apps like Facebook and Twitter, and search phone messages for any religious language. According to a new report released by Human Rights Watch, China has created a massive centralized database that tracks troves of private information on Xinjiang’s citizens, information such as a person’s “health, family planning, banking, and legal records.” China has also rolled out wi-fi “sniffers” to surreptitiously gather data from people’s smartphones and computers. Cameras with facial recognition and infrared technology have been placed throughout Xinjiang, pointed at anything from entertainment venues to supermarkets and even schools. All of this data can be used to send Uyghurs or others in Xinjiang to the political re-education camps.

Against this backdrop of increasing state repression, prominent Uyghur cultural leaders and academics put their liberty at risk simply by being a voice for their culture. One notable case is Ilham Tohti, winner of PEN America’s 2014 Barbara Goldsmith Freedom to Write Award, who is now serving a life sentence for his efforts to foster greater cultural harmony within the Xinjiang region. Prominent Uyghur scholar Rahile Dawut has also recently disappeared—her whereabouts currently remain unknown. The treatment of these peaceful scholars, portrayed as extremists by the state, is a threat to global scholarship. And it is not just scholars: Musicians, athletes, and poets have also been targeted.

The Chinese government’s “anti-extremism” policies in Xinjiang are a large-scale attack on freedom of expression, and human rights more broadly. People in the region are not free to express their culture or their faith. The international community, and all those who see themselves as advocates for free expression, has a moral imperative to speak out. In fact, this last week members of the U.N. Committee on the Elimination of Racial Discrimination (CERD) forcefully lambasted the Chinese government for these “massive internment camps,” but Chinese diplomats denied the allegations, despite the mountains of evidence.

The world cannot fall for these denials; we must call loudly and repeatedly for China to put an end to this human rights travesty. We must do so not only on behalf of those who are suffering now but as a rejection of the dystopian future that these policies represent.