In the most severe cases, crushing has involved homicide[3] or extended torture until death of restrained animals including dogs, cats, pigs, and monkeys. Animal welfare organisations, such as the Humane Society of the United States, condemn this practice and consider it extremely disturbing.[2] The motivation for these acts may be the production of a film recording the events, which is sold on the Internet to crush fetishists who find the content sexually gratifying; a tailored genre known as 'crush film'.