> also, what scale of harm do you think exists from those people?

Serious health complications, particularly to cyclists and pedestrians. Significant pollution surges:

> According to government estimates, the practice can increase nitrogen oxide emissions as much as 310 times, non-methane hydrocarbons 1,400 times, and carbon monoxide 120 times. [https://www.rawstory.com/raw-investigates/rolling-coal-donal...]

> AED estimates that the emissions controls have been removed from more than 550,000 diesel pickup trucks in the last decade. As a result ofthis tampering, more than 570,000 tons of excess oxides of nitrogen(NOx) and 5,000 tons of particulate matter (PM) will be emitted by these tampered trucks over the lifetime of the vehicles. [https://int.nyt.com/data/documenttools/epa-on-tampered-diese...]