Others may also use vibrators and other sexual devices more commonly associated with female masturbation. However, the tradition of bondage magazines continues in the form of art books of bondage photographs, published by mainstream publishers such as Taschen. As a result, little in history was documented to give an accurate description of how female homosexuality is expressed. Fisting pornography features the insertion of an entire hand into a performer vagina or anus. Although pornography has usually focused on heterosexuality, due to the prevalence of the heterosexual orientation, explicit gay material has a long history as well, which reaches back to Greek antiquity, if not to prehistory. Some do not use the diapers at all, for arousal, or bladder and bowel movements. This is why video stores might consider stocking transgendered subject matter in the straight section, as some straight men will have passive or active sex with another man as long as their partner appears to look like a woman to them, to some minor or major degree. People may engage in anilingus for its own sake, before anal fingering or penetration, or as part of foreplay. Actual spying may violate privacy and/or trespassing laws in many countries. A somewhat controversial ejaculation control technique is to put pressure on the perineum, about halfway between the scrotum and the anus, just before ejaculating. Some techniques which may work for one individual can be difficult or uncomfortable for another. A celebrity may allow such a recording to surface willingly, as part of a publicity gay sex stunt. Simultaneous penetration of the mouth and either the vagina or anus. High heel pornography involves women or men dressed in high heeled shoes. Insertion in pornography features women inserting various odd objects into their anus or vaginas. Actual upskirt or downblouse shots may violate privacy laws in some countries. Snuff pornography involves the actual death of any of the participants, consenting or otherwise, simulated death is not considered snuff.