At first, their activities were limited to large urban areas. But these two gangs now have more than 1,000 affiliates in more than 100 cities. Almost half of these cities with Crips and Bloods associates are small to midsize, with populations of less than 100,000. Because drugs often yield much higher profits in small cities and in rural areas than they do in big cities, members of both gangs have moved to smaller cities and set up distribution networks that reach back to their counterparts in the large cities and sometimes to the major international trafficking groups. Street gangs frequently have ties to prison gangs.
Leaders are often former prisoners and take their orders from fellow gang members still in prison.
At first, they focused on riding motorcycles and throwing wild parties, but they increasingly turned to violence. In 1947, a group of outlaw bikers attending a motorcycle rally destroyed the town of Hollister, California, when one of its members was arrested. The biker gangs gradually moved into criminal pursuits, often working closely with the traditional mafia. Today the four major biker gangs are the Hells Angels, the Outlaws, the Bandidos, and the Pagans. A significant source of income for most biker gangs is drug trafficking, especially the manufacture and distribution of methamphetamine.