I undid his edit.  I then just commented out the categories he is determined to just delete.  I didn't change the edit summary, but he should have checked before incorrectly using rollback and incorrectly accusing me of vandalism.  My edit was in _no_ way inappropriate.  Misuse of tools is the first step to them being removed.  You find the comment "extremely chilling"?  You clearly live in a whole different world from me!