When you become so enraged, that you begin to giggle uncontrollably. Not laugh, not guffaw...giggle. May be accompanied by vocalized plans of an overly elaborate and unnecessarily messy end to the source of said rage.
"I hate these stupid phones at work so much (giggling angry)...I'm going to put them into a bag, and then (giggling), I'm going to smash them all to bits with a sledgehammer, and then (giggling) I'm going to blend the smashed bits until they are dust (more giggling)...and then I'm going to burn the blender with the dust, just to be sure.....(giggling, evil smile)