In the States, for example: Every state I've looked at has laws that make it illegal to roll coal.
And at least in my own state (Ohio), it's a primary offense. A person can be pulled over and ticketed for this even if they're doing everything else by the book. It's super easy to spot.
It seems that it persists not because of a lack of laws, but because of a lack of enforcement.
also, what scale of harm do you think exists from those people?
do you really believe that control of one’s own engine should be removed from all vehicle owners if a few people misuse it?
do you understand that vehicle manufacturers use their proprietary systems that control the vehicle to exploit customers?
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...]