The death of Dutch amateur linesman Richard Nieuwenhuizen shocked a nation. Niewenhuizen was beaten to death following a youth match, with six teenagers and a father set to face trial over the killing. Nieuwenhuizen's death prompted a rule change in Dutch soccer, meaning that only team captains can speak with referees -- any other player who does so will be booked.
Tragic death —
The death of Dutch amateur linesman Richard Nieuwenhuizen shocked a nation. Niewenhuizen was beaten to death following a youth match, with six teenagers and a father set to face trial over the killing. Nieuwenhuizen's death prompted a rule change in Dutch soccer, meaning that only team captains can speak with referees -- any other player who does so will be booked.
ROBIN UTRECHT/AFP/Getty Images/file
A year previously, AZ Alkmaar players angrily protested when referee Bas Nijhuis sent off the club's goalkeeper after he kicked out at a fan of opposing team Ajax who attacked him during a Dutch Cup match.
New rules —
A year previously, AZ Alkmaar players angrily protested when referee Bas Nijhuis sent off the club's goalkeeper after he kicked out at a fan of opposing team Ajax who attacked him during a Dutch Cup match.
OLAF KRAAK/AFP/Getty Images
Graph showing figures before and after rule change —
Max Klein, left, is a young, up-and-coming referee in Germany. The 18-year-old thinks the only way clubs and fans will truly change their conduct is if they are hit with heavy fines.
The next generation —
Max Klein, left, is a young, up-and-coming referee in Germany. The 18-year-old thinks the only way clubs and fans will truly change their conduct is if they are hit with heavy fines.
Max Klein
Herbert Fandel is a former referee who is now head of the German Football Federation's referee commission. He admits violence is one of the reasons why the number of officials in Germany is decreasing.
View from the top —
Herbert Fandel is a former referee who is now head of the German Football Federation's referee commission. He admits violence is one of the reasons why the number of officials in Germany is decreasing.
Vladimir Rys/Bongarts/Getty Images/file
Chelsea players raged at referee Tom Henning Ovrebo after he failed to give what they considered to be multiple penalties during a 2009 Champions League semifinal second leg against Barcelona. The Norwegian says players and coaches should be educated on the psychological impact abuse has on referees.
Blue rage —
Chelsea players raged at referee Tom Henning Ovrebo after he failed to give what they considered to be multiple penalties during a 2009 Champions League semifinal second leg against Barcelona. The Norwegian says players and coaches should be educated on the psychological impact abuse has on referees.
Clive Rose/Getty Images/file
Real Madrid coach Jose Mourinho named Ovrebo and a number of his colleagues in a list of referees he considered to be sympathetic towards Barcelona. "I can't say what I feel. I only leave one question. Why?" said Mourinho after a 2011 Champions League semifinal loss to Barca. "Why? Ovrebo, (Massimo) Busacca, (Anders) Frisk, (Wolfgang) Stark, (Frank) De Bleeckere. <br /><br />"Why to all these people. Each semifinal always brings the same. We're talking about a fantastic football team. So why?
Mourinho's ire —
Real Madrid coach Jose Mourinho named Ovrebo and a number of his colleagues in a list of referees he considered to be sympathetic towards Barcelona. "I can't say what I feel. I only leave one question. Why?" said Mourinho after a 2011 Champions League semifinal loss to Barca. "Why? Ovrebo, (Massimo) Busacca, (Anders) Frisk, (Wolfgang) Stark, (Frank) De Bleeckere.

"Why to all these people. Each semifinal always brings the same. We're talking about a fantastic football team. So why?
LLUIS GENE/AFP/Getty Images/file
The English Premier League has instigated a "Respect" campaign in a bid to stop match officials being subjected to abuse -- such as this during match between Queens Park Rangers and Stoke in May 2012.
Referees faced with violence —
The English Premier League has instigated a "Respect" campaign in a bid to stop match officials being subjected to abuse -- such as this during match between Queens Park Rangers and Stoke in May 2012.
GLYN KIRK/AFP/Getty Images