Civil disobedience with bite. The problem with most types of political behavior (like voting and even protesting) is that they assume change has to come from those you vote into power or those who are in charge of the policies you oppose.

Direct action results from impatience. No longer are you asking or even demanding, but you take personal responsibility for what should happen. Even a general strike is only mild action, because it still hinges on changing the behavior of the capitalists who lay claim to controlling the company. Concrete direct action ignores them altogether by replacing their authority - for example, employees may simply assume control over the day-to-day running of the company, and only pay attention to the actions of the capitalist when he actually attempts to do harm to individual workers.