Street racing is a form of unsanctioned and illegal motor racing which takes place on public roads. Street racing can either be spontaneous or well-planned and coordinated. Well coordinated races are planned in advance and often have people communicating via 2-way radio/citizens' band radio and using police scanners and GPS units to mark locations of local police hot spots. Street racing is reported to have originated prior to the 1930s due to alcohol prohibition in some parts of the United States.Opponents of street racing cite a lack of safety relative to sanctioned racing events, as well as legal repercussions arising from incidents, among street racing's drawbacks.[citation needed]