Website tracker DownDetector recorded the outage just before 6pm.
The platform had a massive one-day loss of more than $300 billion off it's stock-market.
It comes as the company shifts focus to virtual and augmented reality.
The post tells users to call an 0800 number to get credit and has resulted in hundreds of calls to an NZAF helpline.
Austin Carr said the Facebook CEO is portrayed somewhere "between naive genius and robotic robber baron" in the new book.
