Despite the city's reputation, most crimes against tourists are of the purse-snatching and pickpocketing variety that can be avoided with a little common sense. Avoid displays of wealth, such as expensive jewelry or watches. Never accept any food or cigarettes from a stranger and be wary of any unknown person approaching you on the street, especially if they are well dressed and overly friendly. Don't be duped by people claiming to be plainclothes police officers who demand to "register" your money -- they are almost certainly thieves. In case of such confrontations, you may want to hand over a $20 bill to quickly extricate yourself from the situation.