Nuclear reactors entail massive non-transferrable site-specific investments. The resulting appropriable quasi-rents offer the mob the ideal target. In exchange for large fees, it can either promise to "protect" the utility (and silence the reactor's local opponents) or "extort" from it (and desist from inciting local opponents). Using municipality-level (1742 cities, towns, villages) and prefecture-level (47) Japanese panel data covering the years from 1980 to 2010, I find exactly this phenomenon: when a utility announces plans to build a reactor, the level of extortion climbs.Reactors have broad-ranging effects on social capital as well. In general, the perceived health costs to nuclear power are highest for young families. As a result, if a utility announces plans for a new reactor, these families disappear. Yet these are the men and women who invest most heavily in the social capital that keeps communities intact. When they disappear, reliance on government subsidies increases, and divorce rates rise. Firms stay away, and unemployment climbs. * Mitsubishi Professor of Japanese Legal Studies, Harvard University. I gratefully acknowledge the hospitality of the University of Tokyo Law Faculty, and the generous financial support of the Harvard Law School. I received helpful comments and suggestions from Daniel Aldrich, Curtis Milhaupt, Eric Rasmusen, and workshop participants at