Screenshot via YouTube.
A group of anti-environmentalists and truck enthusiasts have been modifying their diesel truck engines with smoke stack kits so their vehicles release thick clouds of black soot onto bystanders or Prius drivers.
This practice, which has been nicknamed "rolling coal," has congealed into an Internet subculture covered by Vocativ in a recent article. Practitioners post photos of their modified Ram trucks and Chevrolet Silverados with smoke stacks at times referred to as "Prius Repellent."
