I Can Crash Your iPhone with a Text Message
A bug in iOS, Apple's operating system, allows anyone to send a text message and crash an iPhone. Or an iPad. Or an Apple Watch. Or even a Mac computer.
When you get a text message, you usually receive a truncated preview of the message in a banner. The bug, discovered by Reddit users, can be exploited when someone using an iOS device receives a text in non-Latin script, which includes Arabic, Chinese and Marathi. The problem occurs because iOS has trouble rendering the ellipsis (the ... at the end of the message). When this happens, the device will crash and reboot.
As easy as this sounds, the text actually has to be very specific, so it's unlikely to happen by accident and is actually being used as a prank. Unfortunately, some of the victims of this bug report they can't access Messages after the crash. There's a reported workaround for that though: Send a photo via text using the Share button in Photos. This will let you view your message history and delete the conversation that caused the crash.
iMessage is not the only way to exploit this bug though. Other apps that send you banner notifications can cause it as well.
If you're worried about this happening to you, the easiest thing to do is to disable notification banners.