Illegal taxicabs, sometimes known as pirate taxis, gypsy cabs, or jitney cabs, are taxicabs and other for-hire vehicles that are not duly licensed or permitted by the jurisdiction in which they operate. Most major cities worldwide require taxicabs to be licensed, safety-inspected, insured as for-hire vehicles, and to use taximeters, and there may also be requirements that the taxi driver be registered or accredited. However, many unlicensed cabs are in operation. Illegal cabs may be marked taxi vehicles (sometimes referred to as "speedy cabs"), and others are personal vehicles used by an individual to offer unauthorized taxi-like services. Illegal cabs are prevalent in cities with medallion systems, which restrict the number of legal cabs in operation. Since their introduction in 2009, vehicles affiliated with ridesharing companies have been classified as illegal taxicabs in some jurisdictions.