assaults of madmen

How can society protect itself from the unprovoked assaults of madmen? There are two questions here: 1) how can such be prevented? 2) who should do the prevention? As for the latter, surely the answer is those at blame? But we are a jointly-imagined whole, jointly-responsible. Each of us contributes his part to an atmosphere which breeds behavior of an "antisocial" nature. Even fiction still has a cause; even the drunken careen of mad imagination cannot arise without external catalyst. We provoke the disturbances of the susceptible, and through our ignorance encourage them. So "society" is to blame for its internal detractors, but also "society" is a mere intangible epiphenomenon, laid upon the noise of individual behavior. How then can we address the former; how then can we act? We each must succor the potentially estranged separately, as jointly there is no we, but merely a collection of Is. We cannot trust a mere fantastickal apparition, but each separately must carry the load of all. The duty of the individual cannot be foisted upon the shoulders of an imaginary giant.