It's actually bosozoku. To translate it, boso which the o's are actually long o's, means to run around crazy or out of control. Zoku means like a group.

These guys are a menace on the streets. Honestly. They almost always have bats or chains somewhere, take up every single lane of a street or highway, almost all their cars and motorcycles are stolen, and do nothing but cause trouble. And there are thousands of them. If they pulled the crap that they pull in Japan in Canada or the US, there would be some deaths going on I think. In fact there was one story where somebody had put piano wire across a road that they frequented a lot. The guy (they never found out who) must have been sick of being hassled every single night with the loudness and when a few went by on their bikes, one of them was decapitated. It was about that time that the police decided to crack down on them a bit. At least in that area of the city....

There are some very very weird cars and bikes out there. It's amazing what they get away with too. I've literally watched the cops laugh as they drive by with their revving of engines, swinging of bats and chains etc and holding up miles of traffic.. it's insane.