Recent developments in neuroscience have inspired proposals to perform deep brain stimulation on psychopathic detainees. We contend that these proposals cannot meet important ethical requirements that hold for both medical research and therapy. After providing a rough overview of key aspects of psychopathy and the prospects of tackling this condition via deep brain stimulation, we proceed to an ethical assessment of such measures, referring closely to the distinctive features of psychopathic personality, particularly the absence of subjective suffering and a lack of moral motivation. Scrutiny of these factors reveals that two essential bioethical criteria, individual medical benefit and voluntary informed consent, cannot be met in performin...