Just rewatched the new Dune movie and had to explain to a friend why melee combat is a thing. I then started wondering: this could very well be used as an offensive weapon. Emphasis by me:
Lasguns were the preferred weapon for armies. However, when shields were being employed, lasguns were generally not used because contact reaction between a lasgun beam and a shield created a nuclear explosion that often killed everyone within a large radius.
From the Dune Fandom article on Lasguns
So, basically, a faction could be using this as a deterrent for other factions (if you attack us, we are using the lasgun, attack us at your own peril) or simply sending one single guy into the enemy camp shooting somebody using a shield with a lasgun.
I figure noble houses would probably not do this (maybe an accord that is enforced by them all?) but I assume there might be factions with less ethical concerns (not implying Harkonnens have such concerns). So, is that tactic used by a faction? If yes, which? If no, why not?