Individuals who sold or transported illegal alcohol during prohibition were known as bootleggers. These individuals knew they were breaking the law but continued to sell alcohol due to the huge amount of profits they were able to make. Bootleggers became extremely wealthy but often had to compete with other bootleggers for customers. This competition among bootleggers resulted in the development of gangs, in which there were several violent events that took place due to these rivalries (interested in learning more, check out "Valentine's Day Massacre).