https://www.bleepingcomputer.com/news/security/chinese-censorship-bug-caused-iphone-crashes-when-receiving-taiwan-flag-emoji/

In a bizarre case of what appears to be Chinese censorship gone wrong, Apple introduced a bug in iOS that could cause an app to crash if a user received the Taiwan flag emoji and had their region set to China. This would allow remote users to essentially perform a denial-of-service on a receiving messaging application by constantly sending the emoji.

According to a blog post by security researcher Patrick Wardle, he discovered this bug when a friend told him that iOS apps would crash when she types the word "Taiwan" or received a message with the Taiwanese flag.