I like this thread. It could prove to be a most interesting study and insight into a cyberbully's mind.
The objectives of bullies are Power, Control, Domination, Subjugation. They get a kick out of seeing you react.
It doesn't matter how you react, the fact they've successful provoked a reaction is, to the bully, a sign that their attempt at control have been successful.
After that, it's a question of wearing you down. The more you try to explain, negotiate, conciliate, etc the more gratification they obtain from your increasingly desperate attempts to communicate with them.
Understand that it is not possible to communicate in a mature adult manner with a disordered individual who's emotionally retarded.
For this reason I will cease to comunicate with our resident cyber bully. Instead I shall study his posts objectively and forward my findings to various anti-bully websites.
Thank you Rover.