For many years, Chinese users of Apple devices have had a very different experience from non-Chinese users. Chinese users can’t type or see the Taiwanese flag emoji (which has even caused severe bugs in the past); iCloud backups and encryption keys for Chinese users are stored locally within China; content services like iTunes Movies and iBooks are either not available or asked to step carefully around damaging China’s image; and the “curated” App Store’s selection criteria is markedly different, forbidding tools like VPNs which are prevalent in the rest of the world.

As the Chinese mainland government and Hong Kong population struggle over the extent to which their shared “one country, two systems” is applied, these differences have started to show in the special administrative region too. Last week, as part of an iOS update, Apple extended the Taiwanese flag emoji ban to Hong Kong and Macau. Under pressure from the authorities, it has censored applications there as well, despite worldwide criticism. Apple’s recent expansion of content restrictions into Hong Kong is extremely concerning, especially since Apple’s strictly walled gardens give it nearly unilateral control over this content.

Because so much of its supply chain—not to mention a valuable consumer market —is tied to China, Apple seems particularly vulnerable to Chinese state pressure. But Apple’s ability to enforce these experiences—and users’ inability to evade them—comes from the locked-down design of Apple products. Systems built and sold on the basis of increasing the privacy and security of their end-users risk being turned against them, as the motives and interests of Apple the company shift away from that of Apple’s customers.

When Apple’s Crystal Prison is Filled By The Chinese State

Unlike on Android, iOS users can’t side-load applications without first jailbreaking their phone entirely. Apple’s closed application ecosystems enables Apple to enforce rules about application content and take them down at any time.

This gives China a powerful hammer in the Apple ecosystem. In the second half of 2018 alone, Apple removed five hundred applications in mainland China to comply with local regulations. Greatfire’s AppleCensorship project detected over two thousand applications currently available in the U.S. that are not available in mainland China. Unavailable apps include censorship circumvention software like Tor and VPN apps, foreign software services like Google Earth, and news outlets like the New York Times. One of the most recent additions to this list is Quartz, which was removed following its reporting of the demonstrations in Hong Kong.

Apple’s policies for Hong Kong’s app store stood outside the heavy-handed rules of mainland censorship until recently, when Apple capitulated to state pressure to remove, a crowdsourced map application being used by protestors to track protest hotspots as well as events to avoid, like tear gas deployments and large gatherings of police. Because Apple’s App Store is the only app store for Apple devices, China can make this software effectively non-existent for Chinese, and now Hong Kongese, Apple users.

When “Safe Browsing” Can Feel Decidedly Unsafe

Researchers recently noticed a new clause in Safari’s Privacy & Security policies about sending some amount of browsing data to Chinese tech company Tencent to check whether a website is “fraudulent.” Apple has since confirmed that this works the same way as Google’s safe-browsing endpoint, and that Tencent is only consulted for devices with their region code set to mainland China.

Though only hash prefixes are sent, Tencent is still responsible for curating the blocklist, and has a history of conflating security-preserving measures with content censorship. Their QQ Browser, among other fundamental security and privacy flaws, uses a similar “security mechanism” to block website access on the client. On QQ Browser and many other Chinese browsing clients, the Github repository for a tech worker labor movement was blocked via the same mechanisms that are usually used to identify and block phishing sites. Thanks to widespread web encryption, and the fact that Github is too economically useful to China for the government to block entirely at the network level, browsers needed to resort to this workaround for client-side censorship of specific pages.

Apple Controls Its Ecosystem: But Who Controls Apple?

There’s some solace here that in Safari at least, we still have the option to turn this filtering off. But inserting content censorship or broader “public safety” interests into a narrow security mechanism is a dangerous road. As Apple commentator John Gruber points out, the very least that Apple owes its customers is proactive clarity and transparency when it farms out its huge responsibility to protect its users (and capabilities to control their experience) to third parties like Tencent.

Apple’s arguments for their strictly locked-down, DRM-laden garden include the stronger security and privacy standards it sets for applications by reviewing them. But by centralizing and monopolizing that power, it creates yet another powerful lever through which governments or other actors that have power over Apple can impose their control over these most personal of personal devices.