Idling—the gas-guzzling, toxic fume-spewing practice of leaving your car engine running without moving—has long been denounced by environmental activists and, increasingly, by legislators as well. New York has some of the strictest anti-idling laws in the United States, though enforcement has been lacking. Which is not a surprise when NYPD officers are seen idling in their cars, too.

Some New Yorkers, such as George Pakenham, have taken it upon themselves to submit thousands of Citizen’s Air Complaints to the city's Department of Environmental Protection, alerting them when vehicles idle their engines for longer than three minutes or for longer than a minute next to a school. Pakenham, an environmental activist who works in finance, has been a vigilante submitting complaints for over ten years—and, as he recently told Vice News, he's made a staggering $9,000 from submitting 120 reports on idling vehicles.

The City Council recently increased the rate for citizens taking idling matters into their own hands. If a complaint goes through, the person who reports it can get paid 25% of the $350 fine—or roughly $87.50, as The New Yorker reports. "The I.T. guy at the D.E.P. has created a Dropbox for me,” Pakenham, who has produced a documentary called Idle Threat: Man On Emission about this particular practice, told the magazine last year.

His interest in this, as he recently told Vice, happened following the fallout of the Iraqi War. At the same time, Pakenham's brother was diagnosed with stage four lung cancer, despite never having been a smoker. (Idling engines can result in lung irritation, as well as increased risks of conditions including cancer and asthma) "I began to witness and observe trucks and buses in the city, at curbsides, idling their engines," he says in the video. "And I said, 'Boy this is an interesting situation, since we went to war for oil, and these people are wasting oil we went to war for.' I never dreamed it would migrate into a national law where I'd be able to benefit."

Check out the trailer for Pakenham's documentary below: