Even in a country known for its extreme spying on its entire population, the degree of surveillance targeting Muslims in particular is unnerving. An estimated 22 to 25 million Muslims live in China, out of a total population of 1.4 billion. Last year, a Freedom House study found that extensive surveillance affects many religious groups, with Muslims as well as Protestant Christians and Tibetan Buddhists experiencing an increase in persecution over the previous five years. In an interview this week, Timothy Grose, a China expert at the Rose Hulman Institute of Technology, told me, “Right now, we see a lot of the repression being directed against Muslims.”

Chinese tech isn’t the enemy

The Dove program’s bird-like drones have been flown over five provinces so far, and it’s perhaps no coincidence that they’ve been used extensively in one area in particular: Xinjiang, a northwestern region heavily populated by Uighurs, a largely Muslim ethnic minority. The government has long considered the region a breeding ground for separatism and extremism. Ethnic riots there killed hundreds in 2009, and some Uighurs have perpetrated terror attacks in recent years. The area is now subject to a heightened level of surveillance, with authorities collecting DNA samples, fingerprints, iris scans, voice samples, and blood types from residents.

“They’re applying a very, very broad attempted solution to what they see as an ideological danger. In Xinjiang, the definition of extremism has expanded so far as to incorporate virtually anything you do as a Muslim,” James Millward, a professor of Chinese history at Georgetown University, told me. The amount of surveillance directed at that region’s 11 million Uighurs, he added, is “certainly disproportionate” relative to that directed at other groups. “Islam is now effectively being demonized in China.”

This month, 11,500 Chinese Muslims are heading to Mecca on the annual Hajj pilgrimage. Before leaving the country, some of the pilgrims were given state-issued tracking devices, in the form of “smart cards” attached to lanyards around their necks. The devices bear GPS trackers and customized personal data. The state-run China Islamic Association says they’re intended to ensure the pilgrims’ safety. (There is legitimate reason for such concerns: During the 2015 Hajj, a stampede killed more than 750 pilgrims.) But some human-rights experts say this is one more effort to surveil Muslims. The government’s fear, according to a Human Rights Watch report, is that religious pilgrimages could act as “potential cover for subversive political activity.”

“I don’t use what comes out of human-rights organizations uncritically, but here’s one case where I would definitely side with them,” Grose said. “The pilgrims are always accompanied by an official guide, essentially a monitor, who represents the Chinese Islamic Association, which represents the state. Their movements are always under supervision. Their schedules are airtight, with very little room for any extracurricular activities. So the use of GPS in an already tightly put-together schedule just seems too redundant [if it’s about safety]. To me, it’s about: ‘Well, what if one of them sneaks away, and we need to find out where he is and if he’s talking to someone and bringing back with him an interpretation of Islam that doesn’t accord with [what the government] has been promoting?’”