total and utter hoax. just the fact that people are being arrested just for watching the video to determine if it's real or not speaks volumes.
but when you watch the video, especially slowed down, you see he's firing blanks and nobody is getting killed. the more you watch it, the more you realise that people are not dying in a horrific massacre designed to disarm nz, but taking part in another stage play.
here's some more info, also worth reading the comments: