If you’re in China and running iOS 11, try sending an emoji of a Taiwan flag to someone else. You might find something rather odd: it doesn’t work.
That’s the claim made by security researcher Patrick Wardle who recently dug into Apple’s mobile operating system to see why a friend’s phone kept crashing every time they tried to send a Taiwan flag to someone else. He discovered, after digging into Apple’s code, that iOS 11 blocked the emoji in Apple’s own iMessage, as well as messaging apps WhatsApp and Facebook Messenger. The phone would also stop working when people would type Taiwan.
In a blog post, Wardle explained in deep technical detail how it works. Essentially, if you set your iPhone or iPad’s device language or location settings to China, or “CN” on the code side, the operating system will block the Taiwan flag emoji from being displayed. If the operating system’s settings are set to any other country or region, the flag is allowed.
Wardle did a bit more digging and found on Emojipedia, a site that tracks emoji, a story from April that Chinese iPhone users don’t have access to the Taiwan emoji. Wardle also linked to a MacRumors forum, where iPhone users complained of not being able to use the Taiwan emoji in China.
So, what’s going on? It’s hard to say. But politics—and Apple’s relationship with China—might be playing a role.
Taiwan, of course, is self-governing and considers itself independent of mainland China. However, the Chinese government has long desired taking control over Taiwan. The U.S., among many other countries and international bodies, won’t recognize Taiwan as an independent state.
Meanwhile, China is one of the most important markets to Apple. And given the relationship China has with Taiwan, the company might be appeasing the Chinese government with its flag blockade.
“Does Apple really add code to iOS to appease the Chinese government?” Wardle asks in his blog post. “Of course!”
Apple did not immediately respond to a Fortune request for comment.