An animal that is liking being petted pushes against the hand, and seems to enjoy it. To those defending bestiality this is seen as a way in which animals give consent, or the fact that a dog might wag its tail. Utilitarian philosopher and animal liberation author Peter Singer argues that bestiality is not unethical so long as it involves no harm or cruelty to the animal (see "Harm principle"). In the article "Heavy Petting," Singer argues that zoosexual activity need not be abusive, and that relationships could form which were mutually enjoyed. Singer and others have argued that people's dislike of bestiality is partly caused by irrational speciesism and anthropocentrism. Because interspecies sex occurs in nature, and because humans "are" animals, supporters argue that zoosexual activity is not "unnatural" and is not intrinsically wrong. Research has proven that non-human animals can and do have sex for non-reproductive purposes (and for pleasure). In 2006, a Danish Animal Ethics Council report concluded that ethically performed zoosexual activity is capable of providing a positive experience for all participants, and that some non-human animals are sexually attracted to humans (for example, dolphins). Some zoophiles claim that they are not abusive towards animals:  "In other recent surveys, the majority of zoophiles scoffed at the notion that they were abusive toward animals in any way—far from it, they said. Many even consider themselves to be animal welfare advocates in addition to zoophiles." Because of its controversial nature, different countries vary in the discussion of bestiality. Often sexual matters are the subject of legal or regulatory requirement. In 2005 the UK broadcasting regulator (OFCOM) updated its code stating that freedom of expression is at the heart of any democratic state. Adult audiences should be informed as to what they will be viewing or hearing, and the young, who cannot make a fully informed choice for themselves, should be protected. Hence a watershed and other precautions were set up for explicit sexual material, to protect young people. Zoophile activity and other sexual matters may be discussed, but only in an appropriate context and manner. The IPT was replaced after the Films, Videos, and Publications Classification Act in 1993, replaced with bodies designed to allow both more debate and increased consistency, and possession and supply of material that it is decided are objectionable was made a criminal offence.