In London, dubbed the cocaine capitol of Europe, drug lords are experiencing a boom in homegrown marijuana that has turned Britain into an exporting country. While cocaine is the preferred drug for upper- and middle-class Londoners, in the tough housing projects of East London, marijuana reigns as king.In London, dubbed the cocaine capitol of Europe, drug lords are experiencing a boom in homegrown marijuana that has turned Britain into an exporting country. While cocaine is the preferred drug for upper- and middle-class Londoners, in the tough housing projects of East London, marijuana reigns as king.