To put this into context there is a documentary coming out about dirt bikes and 4-wheelers in Baltimore.

http://12oclockboys.com/

I have personally gotten fairly close to hitting a 4 wheeler in ATL and see gangs of them roaming my neighborhood. It seemed to me like they were just having a good time, certainly disturbing the peace and creating dangerous road conditions though. Then again that isn't all too unusual in my neighborhood.