Transcript for Warning Biker Swarms: Flash Mobs on Wheels
Now, a warning about a problem spread ag cross America's streets. Weevil seen the pictures before. Bikers taking over the roads in New York, Philadelphia, los Angeles. Well tonight, it's Miami. ABC's gio Benitez and the newest case that stopped traffic and caused chaos on the highway. Reporter: Tonight, call them modern outlaws wreaking havoc right in the middle of the rush hour commute. Helicopter videos showing hundreds of people on dirt bikes and atvs in Miami speeding on some of the most popular highways, swerving through traffic, popping wheelies, waving at the camera. Even swarming a gas station to fuel up and keep going, all the while, everyday drivers trying to navigate those same roads. We were caught offguard. Reporter: Police saying these swarms are difficult to stop. Puts the officer at risk and puts the person being pursued at risk. Reporter: That Twitter hash tag, bikelife, spreading word about these biking extravaganzas. ABC news riding along with a South Carolina biker asking what they're thinking when they take to the road in packs. It's almost like, when a guy conquers Mt. Everest, and he puts his little country flag up there and takes a picture. That really shows that you kind of beat the system, you beat the cops at their game. Reporter: A dangerous game you can almost bet will continue to be played on our nations highways and our social networks. Gio Benitez, ABC news, New York.
This transcript has been automatically generated and may not be 100% accurate.