Sex in film, the presentation of aspects of sexuality in film, especially human sexuality, has been controversial since the development of the medium. Films which display or suggest sexual behavior have been criticized by religious groups or have been banned or censored by governments, although attitudes have changed significantly over the years and a more permissive social environment has developed in certain parts of the world, notably in Europe, North America, Australia and New Zealand. In countries with a film rating system, films which contain explicit sex scenes typically receive a restricted classification. Nudity in film may be regarded as sexual or as non-sexual.