Racists beware!

The details of this story have been eliminated/changed to protect the not-so innocent.  A few years back while working as a server in a popular restaurant I served a man and his wife who seemed nice enough at first.  They came in during a busy Saturday lunch and after a few minutes they began to find fault with pretty much everything about my service and the food.  As per usual I sent the manger over to diffuse the situation and for whatever reason the guest did not like the fact that the manager's nationality was not American.  He proceeded to let him know this with a couple of racist and unkind comments, to which the manager wisely did not respond.  But he did get his revenge!  After a few minutes the guest had settled down a bit so the manager returned to the table and offered to refill water, the guest said yes and asked for more ice.  The manger then took his glass, brought it into the restroom, scooped out some toilet water, filled it with ice and garnished it with a lemon.  He returned it to the table and said with a smile "there you are sir".  He then came and told me what he had done and we both watched with guilty satisfaction as our esteemed guest enjoyed his "beverage".  Once again the message here is: don't screw with the person serving your food!