Here is video of a total meltdown last night by Women's Tennis star Serena Williams at the U.S. Open after she was called for a "foot fault" during Match Point against Kim Clijsters.
Clijsters led 30-15 against Williams and Williams was serving. The official called her for a "foot fault," giving Clijsters two match points at 40-15. Williams walked over to the official and said something several times. The official then went to the other officials and you can then hear Williams disputing with them saying, "I didn't say I will kill you!" She was assessed a one point penalty, giving Clijsters the match.
NOTE: Corrected. See comments below.