SAN ANTONIO -- The Bexar County Sheriff’s Office is cracking down on black smoke that puts drivers in dangers. They’re on the lookout for rigged trucked releasing plumes of smoke that can blind people while driving.

The videos are all over the internet and drivers are seeing it on our roads.

"I see it all the time, even when I'm driving," said Tim Reyes with O'Brien's Automotive.

Reyes knows cars inside and out, which means he also knows about rolling coals.

"It can go from a very subtle black to a pitch black. It can literally block someone's view or choke someone out," Reyes noted.

"It is something we are seeing more and more as the days goes on," said James Keith with BCSO.

People can modify their own diesel trucks, which could be useful if they need more power to pull a trailer or more speed on the road. But some people are abusing it, and when they release thick, black smoke it becomes a safety concern.

The sheriff's office is worried about other drivers who end up near one of these trucks.

"I don't know if it’s growing in popularity because people can get tools to modify their engines easier or if it's YouTube videos making it more popular,” Keith said. “For whatever reason we are seeing more cases and we are also starting to crack down.”

Deputies are handing out citations for safety hazards, tickets that can cost hundreds of dollars.