Just a remark here.
By its very definition, a free market is free of violence. The reasons why can be studied on mises.org :-) .
What is usually called capitalism is in fact mercantilism, that is a system, where certain groups of entrepreneurs lobby for state privileges to hinder the free market from working. There is, in fact, no difference between those ctions and the way labor unions try to get priviliges to force others into submission. Any hampering the market by means of violence is an evil act and it just makes no difference if entrepreneurs or laborers or whatever other group tries to employ them.
Free market is not the freedom of capitalists and entrepreneurs to opress the masses, it is quite the opposite. The real power is in the consumer, and that is something neither the laborers nor the capitalists or entrepreneurs like to much.