Two groups of hackers (4Chan & Anonymous) are laying claim to web attacks against MasterCard, PayPal, Visa, and Post Finance( a Swiss bank). Any business causing harm to Wikileaks will in exchanged be harmed.
This is not a picturesque example of free market defense, although we do not choose how free market defense will emerge. To each it's own form, these businesses stand on no moral ground. They enjoy a government granted oligopoly and I bid them no compassion.
This is how the Free Market defense works, activist see a worthy cause and rally around it. Some with support, some running interference. If governments do the inevitable and harm Julian Assange they will bring the wrath of Wikileak's secret cables upon themselves. This is the end game, anyway it plays out, it is Wikileaks for the win.