The first time I experienced thermals I stated they are a game changer, a description not surprisingly used by most when they see them in action. For ethical hunting, no, I consider them cheating. For problem animal/pest/vermin control they are without parallel. The ability to "see" animals that would otherwise be invisible, even to night vision which still relies on an amount of available light is amazing. Add to that the ability to go about the business of selective pest destruction without disturbing other animals or people, watch a few Youtube vid's of rats, pigeon's etc being removed from barns and chook houses while the domestic animals sleep peacefully. One night out with the Father in law and a mate who runs a sideline pest control business I shot a rabbit not 20 yards away, thinking he was safe in the grass. We had been talking beside the ute, complete with all it's canopy lights on, for a good 15 mins and he would have been there the whole time.
Another guy I know conducts similar operations around our capital city with a suppressed .300 BLK and thermal scope, the city residents blissfully unaware he's out there. Pro's & Con's for this capability too I suppose.