Critics of every social insurance proposal in the U.S., including recent health care reform, have called them socialist attacks on private property. To be sure, social insurance is a central pillar of social democracy, and social democratic parties originated in a socialist critique of capitalism. Yet the equation of social insurance with socialism is doubly ironic. The first realistic proposal to abolish poverty by means of universal social insurance was Thomas Paine, who explicitly advanced his scheme as a defense of private property against socialist revolutionaries. And the first actual social insurance scheme was introduced by Otto von Bismarck, who advanced it against the German Social Democratic Party, which opposed his plan. This talk will consider how Paine grounded the justification of social insurance in a neo-Lockean theory of private property rights, and explore the implications of the ironic inversion of social insurance from a bulwark of to a perceived assault on capitalism.