Bullies. We all knew one at school--usually bigger than you, typically loud, obnoxious, and cruel, and often pretty dumb.
Often they acted that way to make up for deficiencies in their own lives; today you may meet one who tormented you as a kid pushing shopping carts at your local mall.
Karma can be sweet.
"Rolling coal" is very similar to bullying, only in automotive form.
It involves taking a big diesel truck, and modifying it to spew huge clouds of soot into the air every time the driver stomps on the accelerator.
More recently, drivers of such vehicles have taken to doing it near hybrids, electric cars, cyclists, pedestrians and even the police--to intimidate or simply to make some kind of statement.
Video sites like YouTube are awash in short clips of huge pickups engulfing smaller vehicles in clouds of black soot.
And after experiencing coal-rolling first-hand, one New Jersey lawmaker is working to make the practice illegal in his state.
Last week, he was driving along the New Jersey Turnpike when a lifted pickup truck in front of him--equipped with twin smoke stacks--belched a large cloud of smoke over his car.
He added that he was "surprised" to experience it himself.
He now plans to introduce a bill to make it illegal. Bill A3583 aims to prohibit "retrofitting diesel-powered vehicles to increase particulate emissions for the purpose of ‘coal rolling’".
In theory, the practice is already illegal under federal law and the Clean Air Act. That's because it typically involves removing or modifying mandatory emissions equipment fitted to the vehicles or deliberately altering the fueling to produce greater quantities of pollutants.
However, many of the vehicles to which modifications are made are heavy-duty trucks over 6,000 lbs--such as the Ford F-350--and aren't subject to the same regulations as passenger vehicles.
But the new bill would apply to any diesel vehicle, and allow the Department of Environmental Protection to impose large fines on those violating the law.
Popular perception suggests that drivers are rolling coal to make some kind of anti-environmental statement.
While that might be the case in some instances, Eustace puts it down more to "youthful ignorance".
But it's worth pointing out the vehicle Tim Eustace was driving when that pickup rolled coal in front of him: a Nissan Leaf electric car.