London's main breed of Taxi is the Black Cab. These cars-for-hire are generally used as transport for the rich, and used as population control for the poor or studious. Since these Taxis outnumber cars by a ratio of two to one, there isn't enough custom to allow them to opperate solely as a swift and reliable means of transportation. To broaden their income stream, the Taxi drivers of London also work in the age old profession of 'Crushing on the Side'.
'Crushing on the Side' is, put simply, the practice of running over pedestrians who don't look like they may be potential customers, and taking their valuables, up to and including organs. This practice was legalized by Margaret Thatcher, as a measure to 'rid the streets of students and filth'. The traditional black colouring of the London Taxi is a practical night-time camouflage, although Taxis often go for 'dazzle' pattern paint, which doubles up as advertizing. Often, packs of Taxis will hide in ambush outside student halls, crushing any that attempt to leave through the front doors.
The practice has come under fire from local councils in recent years, for the mess it causes. However, it has been staunchly supported by the tourism agency, tourists enjoying the 'real London experience' of having a shelf-stacker plastered 2mm thick across the wind-screen. Whether a boon to the city, or a mess causing nuisance, the practice is just another quaint custom that makes Great Britain what it is.