Currently, pornography, oral sex (except as a precursor to regular intercourse), and anal sex are illegal in Singapore. Magazines, movies and TV shows have to undergo government classification before being released to the general public and sales of several kinds of newspapers and magazines has been banned or restricted. Various minor offences could lead to heavy fines and caning while conviction of first-degree murder and drug trafficking cases instantly leads to the death penalty. The end result of these policies has been the hanging of more than 400 people in Singapore between 1991 and 2004, mostly for drug trafficking; due to this, Singapore has one of the highest execution rates in the world relative to population. Science fiction writer William Gibson has described Singapore as "Disneyland with the death penalty" [1] in Wired magazine. Chewing gum has been recently legalized as part of a U.S trade agreement. Bans on bar top dancing and bungee jumping have also been lifted.