Law enforcement Monday aggressively addressed the problem.
RELATED: 2 large sideshows in Oakland have some city leaders calling for crackdown
Consider what officers were running into - a sideshow with 100 cars, 1,000 people, shots being fired and fireworks going off. And a bus and truck completely engulfed in flames.
"Shots fired in unknown directions. We had bottles and rocks being thrown at officers and deputies," one officer said.
Video from a deputy running into a sideshow at 42nd Ave. and International Blvd. in East Oakland at 8:30 p.m. Sunday.
"We've been dealing with sideshows for decades but the level of criminality and the boldness - that has gotten way worse with the introduction of firearms into side shows, the arson and the complete lawlessness that's going on has increased," said Alameda County Sgt. Ray Kelly.
Sunday's sideshow morphed into mayhem between 8 p.m. and 9 p.m.
A semi-truck loaded with paper supplies was looted and attacked. "The driver was removed from the cab of his truck at gun point so it's a carjacking. He had been surrounded unable to leave," said Oakland police spokesperson Ofc. Johnna Watson.
RELATED: CHP video gives bird's-eye view of illegal sideshow in Oakland
Police say his truck was torched. They say they were overwhelmed by the crowd. Behind him, an AC Transit bus was stuck and the driver was forced to flee.
It too caught on fire. According to Robert Lyles with AC Transit, the 60-foot articulated coach is just 2 years old and had the latest Americans with Disabilities Act package plus an array of next-generation on board electronics. The coach is valued at greater than $750,000 and is a total loss.
Out of towners, police say, flood into the 880 Corridor from San Jose to Richmond for sideshows, keeping track of police on scanners and communicating privately on cellphones. It's become a regional problem.
"The intersection of 42nd and International is out of control. It's been out of control. We need to create barriers for sideshows," said Oakland City Council member Noel Gallo.
For now, police are going to blitz the area with beefed up patrols starting this weekend, treating sideshows like a mass protest event.
"If we find you and catch you, you're going to jail. We'll take your car," said Sgt. Kelly.
One officer was injured. Police are now shifting through social media posts and surveillance video in the hopes of making arrests.