Once a month, bicyclists converge on downtown's Woodruff Park and begin a two-hour ride through city streets. Well documented with helmet-mounted cameras, the ride is called Critical Mass, with the dual roles of good times and raised awareness.
"It is pretty controversial," said cyclist Stephen Toucet.
It's controversial because the bicyclists of Critical Mass routinely block intersections, regardless of whether they have a red light or green light. Called "corking," they say they do it because it keeps the cyclists together and makes the ride safer.
They admit that some motorists find the practice obnoxious and strongly display their annoyance.
Friday evening, they corked the intersection of Peachtree St. and Eighth. One motorist strongly took exception.
"You can't go through a red light if you're a vehicle," the motorist is heard saying on a YouTube video.
The video, shot by cyclist Matt Todd, shows the driver threatening to strike a bicyclist with his car.
"If you don't move, I'll run you over," he said just a few seconds before putting the car in gear, lightly striking a bicyclist.
The driver dares the cyclists to get his license number as he pulls what appears to be a police badge.
"A badge was the last thing I was expecting to see," said Todd. "And when he pulled it out, it was like, OK. You're trying to intimidate us, you're trying to bully us."
"Because he was a police officer, he had the option of pulling us over and giving us a ticket for going through a red light. I totally accept that," said Toucet. It makes his action inexplicable, said Toucet.
Both bicyclists say they want to file a complaint against the motorist -- if he's a police officer, and if they can ever identify him. They never got a badge or license number.
You Tube Video