If your city’s air is filthy, can you sue the government — and the president too. That’s what a group of people is doing in Jakarta, an Indonesian megacity with some of the foulest air in the world. These residents are sick of wiping black film off their faces at the end of the day. They accuse Indonesia’s government of doing too little to clean up the air. They’re suing not for money, but to shift policy — and if this works, it could provide a model for other people around the world. The World’s Patrick Winn reports.