'What you see in the text is the waving white flag emoji, a zero, and the rainbow emoji. As noted by EverythingApplePro, the emoji string doesn't crash iOS 9, likely because it doesn't support emoji. While the recipient sees a flag emoji, a zero, and a rainbow emoji, the zero is actually a Unicode-based instruction for emoji and other characters - called a variation selector - which iOS 10 can't process. The bug was discovered by a computer science student with the Twitter handle who explains the message will freeze an iPhone when that string of characters arrives via iMessage and is displayed as a banner notification. Google Drive alternative: Decentralized and encrypted