A couple of thoughts...
Operant Conditioning...
We do not want to reinforce negative bahavior. If you engage with morons like this, they get what they want, and that is a rise out of you. So do not engage.
Pepper Spray, Bear Spray
Mark Twain — '
Never argue with an idiot. They will drag you down to their level and beat you with experience.'
And finally.
sprechen sie deutsch
fat biker