The soccer world is full of speculation as investigative reporters attempt to solve a grand mystery.   What set off French player Zidane to react in such an aggressive way?  The main speculation is based upon reports from the anti-racism group based out of Paris, SOS-racism.  They are quoted as saying that  "several informed sources from the world of football" said that the Italian player Materazzi called Zidane a "dirty terrorist" on the field.  Materazzi denied the terrorist comment.  Zizou Zidane was "red carded"  for the head butt knocking him to the ground. FIFA in turn could not comment but stated that they review all red card incidents.