‘Rolling Coal’ in Diesel Trucks, to Rebel and Provoke

“Coal rollers” alter their diesel trucks so they spew thick black smoke, sometimes in the direction of joggers, cyclists and hybrid cars. By Hiroko Tabuchi.
Read more: http://www.nytimes.com/2016/09/05/business/energy-environment/rolling-coal-in-diesel-trucks-to-rebel-and-provoke.html?source=Snapzu