loose the hounds. Send ruthless minions to dispatch intruders without regard to their safety or comfort.
Hounds are hunters, and the kind of hounds you loose are probably killers as well. These might be the kinds of dogs you would call off, though depending on the circumstances or their training, this may or may not be an option. Like the dogs of war (famine, fire, and sword) they are not always controllable once they get out.
Springfield's leading industrialist, Montgomery Burns (of the animated television series The Simpsons) is prone to telling his minion, Smithers, to “Release the hounds!” when the mogul's estate is threatened.