Brian Martin and J0rgen Johansen ask: what makes a protest action effective? Heads of government are coming to town. Let’s organise a protest! We’ll have a massive rally and march. Those who want to can blockade the venue. We’ll make our concerns about inequality, exploitation and aggression known far and wide. But wait a second! Is this sort of protest going to be effective? Is it going to change people’s viewpoints, mobilise support and help bring about a better society? Or, instead, will it enforce prejudices, alienate potential supporters and suck energy away from more effective initiatives? And anyway what does it mean to “be effective”?