This new prank is getting viral on twitter today, By visiting CrashSafari.com on an iPhone, iPad or Mac will cause Safari app to crash and can potentially cause your device to restart.
People are using URL shortener to troll other people. To see a beachball on your mac open safari and visit this website. On the Mac, Safari will freeze (‘Application Not Responding’). You may need to restart your machine to get your browser working again.
On iPhone and ipads this glitch may cause your iOS device to reboot.
9to5mac explains how this prank works :
This prank currently works on Apple’s operating systems, iOS 9.2.1 and OS X 10.11.3 and even on upcoming iOS 9.3