Referees are everywhere. They are in the park. They are in your classroom. They inhabit every boozer and drinking hole that has a TV in the corner. Everyone knows the rules better than the man in the middle.
So during this World Cup there have been some public outpourings of vitriol directed at the real match officials. These men can rarely stand up for themselves and they are in the most exposed situation they could ever imagine. This is the most televised rugby event in history and they are right there in the mix, regularly disappointing one large section of the crowd.