A cannon to a pebble
A very long (sometimes unnecessarily so) response to a comparatively (or even extremely) short argument.
Person 1: Cheese good
Person 2: Actually, due to various dietary studies and research performed by professors at the University of Massachusetts, it has been shown that cheese is actually-....
Person 1: Sheesh, no need to respond with a cannon to a pebble
Person 2: Actually, due to various dietary studies and research performed by professors at the University of Massachusetts, it has been shown that cheese is actually-....
Person 1: Sheesh, no need to respond with a cannon to a pebble