I have two suggestions for the upcoming tennis ball incident.
 
  1. Immediately forfeit the game.
  2. Immediately clear the arena, and finish the game with only the
     scorekeepers and persons in the press box.  ALL FANS ARE GONE.
 
Decide on the action beforehand, and announce it before the start of
the game.  Most importantly, follow through with it.
 
  John H
  U Mich