This video has been making rounds all across the web due to its tendency that a bug can so easily crash an iPhone. All that needs to be done is to open the video in iPhone using a default media player. It would take some time, but your iPhone would be crashed under a minute.
What actually happens is that the video file is corrupt and it tricks your phone into producing a loop by taking advantage of a loophole in iOS’ media-player. iPhones ranging back to iOS 5 are being affected by it. Moreover, the ‘bug’ only bugs your phone when the video is viewed as a link, not as a media file.
WARNING! Like so many other iPhone users, if you have fallen victim to this prank too; remember that it is a minor lock-up and is not permanent. Just reset your iPhone by pressing the sleep/wake and home buttons simultaneously for at least 10 seconds, until you see the Apple logo, let go of the buttons at once and boot your phone.