Nabbing a pesky grey squirrel and cleanly drowning it in a water butt earned this man an RSPCA prosecution and a £1500 fine. It is illegal to release a grey squirrel into the wild so, should you ever be in a position where you have caught one and need to dispose of it, the correct method of dispatch recommended by the RSPCA is to place it in a bag and bang it over the head with a shovel. (Much more humane, obviously) Or you can fork out actual money for a vet to put it to sleep.
Moral of the story is that if you have nosey animal-loving neighbours, wait until nightfall before scattering the slug pellets..... Mad.