There was a bug discovered in the iOS software that will allow hackers to endlessly reboot and there is no way of stopping it from happening as the user. This hack is starting to be so well know these areas are starting to be known as “no iOS Zone”.
This hack works by using a “specially crafted SSL certificate” that triggers a bug in the operating system that crashes out any app using SSL. This will make the device reboot over and over and over again. The only way to stop this hack as iOS user is to leave the wifi's range.
This wouldn't be that bad however there is also another flaw called “Wi-Figate” in which you can force iOS devices to hook up to a wifi. Apple is currently aware of these flaws and is working on patching them.