Sunset Strip was a lawless place between galaxies where gangs ran the city and free trade rules applied. It was a well known trading point with a busy tech market every Tuesday. Detective robots were the main law enforcement force but were often in the pay of the gang bosses and used as minders/protective agents.
The Tenth Doctor, despite a bounty on his head, visited Sunset Strip with Rose Tyler for a cup of Darjeeling and a couple of macaroons. He became involved in a struggle between Don Corpulone and Doll Corpulone over possession of a glitterbird egg. The Doctor got the egg away from them long enough to hatch it. He also reprogrammed a detective robot to enforce the law on Sunset Strip. (COMIC: Gangster's Paradise)