Stealing is in violation of the moral law whether done by a bandit with a gun or by the State under the cloak of legislation. Stealing is no less theft if the money is used for benevolent purposes than if it is used for evil purposes. The social security tax is a way of taking money from one taxpayer in order to give it to another person or group. It is the robbing of Peter to pay Paul.
My two cents
Wow, I never thought of social security in that way; or perhaps more accurately, I was never taught to think of it that way. I’m starting to ask why the modern state often likes to excuse itself from moral law. In response, most of what I get is emotional responses by those who favour (or perhaps covet) cradle-to-grave security.
Mahaffy, F.E. (1957). The Freeman: Ideas on Liberty [online]. [Accessed 17 July 2011]. Available http://www.thefreemanonline.org/featured/a-clergymans-security/print/.