Has anyone ever really done that?

Like shooting fish in a Barrel?  This idiom is so puzzling…  imagine someone learning the English language, what could this possibly mean?  Easy as Pie?  Like taking candy from a baby?  all very curious…  And of course we all assume that there is water in the barrel and the fish are alive and swimming around.  But I agree with the video blogger… what is the point?

content02172017

Quite the defensive reaction in panel two… Guessing Ms. Hunter has heard just about enough of this nonsense… why, her gun is oiled, her rounds are packed, and her trigger finger has the most pleasing itch… can’t we just get to the killing fields already?  Where’s that armor-plated Range Rover?  Let’s go!