Interactive pornography, available in CD-ROM and DVD format, allows the viewer to select the particular acts performed at any one time, sometimes with the camera providing a first person view. Although there may be no connection between coprophilia and sadomasochism , the limited data on the former comes from studies of the latter. Coprophilia , also called scatophilia or scat , is the paraphilia involving sexual arousal and pleasure from feces. Today, pornographic films can be sold or rented on DVD, shown through Internet and special channels and pay-per-view on cable and satellite, and in adult theaters. Patricia Hill Collins, an African-American writer, theorizes that this is derived from a stereotype that those of black descent are promiscuous, and their mature milfs buttocks are objectified by porn as a result. These are often fake. They may be noted for using risqué themes, graphic violence, sexuality or black comedy in a manner that is unsuitable for younger audiences. Mutual masturbation, mutual manual stimulation of the genitals between partners, can be a substitute for sexual penetration. Internal ejaculation shots are a comparatively recent development in pornography; they are not found in early pornographic films. The resulting consent and understanding is occasionally summarized in a written gay hentai contract, which is an agreement of what can and cannot take place. Reality pornography is a genre of pornography where staged scenes, usually shot in cinéma vérité fashion, set up and precede sexual encounters. HIV is among the infections that require such direct contact and is therefore very unlikely to be transmitted via mammary intercourse. Cartoon pornography depicts illustrated or animated fictional characters in erotic and sexual situations. These styles are much closer to the style of bondage scenes in mainstream television. Some pornographic films use an artificial semen substitute to simulate gay boy porn or enhance creampie shots. However, various groups within society considered such depictions immoral, labelling them pornographic, and attempting to have them suppressed under obscenity laws, with varying degrees of success.