'Voluntaryism' is a new word for 'anarchism' being used by pro-capitalist, right-wing "libertarians" who tired of defending their views on the wage system and absentee land ownership from criticism by actual anarchists. Yes, 'actual anarchists'; anarchists are historically and ideologically anti-capitalist. Anarchism is the belief in the creation of human societies where all individuals are free to reach their greatest possible potential absent coercion, not a clean slate where individuals can position themselves above others in society and use that position to extract wealth from their labor.
In contrast, voluntaryists like to reduce all matters of moral action down to the voluntary consent of individuals while completely ignoring presupposed environmental variables which they sneak in the backdoor. For instance, one can easily say that I "voluntarily" pay rent to live in this apartment. And indeed, I of my own will cash my check and deposit the money into the landlord’s account on a monthly basis. Indeed, I signed the contract agreeing to pay this amount monthly. What voluntaryists ignore however, is that I by my very nature do not have a choice in whether I occupy space on the planet, or whether the "right" to occupy that specific space has been claimed by someone else. They ignore the consequences of not paying rent, homelessness, while claiming that the payment of rent represents a voluntary agreement. The threat of homelessness in this case could be easily equated to the threat of an armed robbers gun. Sure it can be said one voluntarily gives up their valuables to the robber if we choose to ignore the coercive variable which compel them to do so, their own necessity. It could just as easily be said that a 19th century English peasant voluntarily accepted monarchy by bowing to royalty if we ignore the law commanding them to do so.
More at: http://isocracy.org/node/107