An anonymous donor has gifted the Guggenheim Museum in New York Xu Bing’s controversial video work A Case Study of Transference , 1994, Artnews reports. The piece, which consists of footage of two tattooed pigs copulating, was removed from the institution’s 2017 survey of Chinese art, “Art and China after 1989: Theater of the World,” after it outraged animal rights activists. While the institution was criticized for taking down A Case Study of Transference and two other works Huang Yong Ping’s Theater of the World , 1993, and Sun Yuan and Peng Yu’s Dogs That Cannot Touch Each Other , 2003it cited threats of violence that were made against the museum’s staff as the ultimate reason behind its decision. The pieces, which involved the participation of live animals in their creation, prompted hundreds of demonstrators to protest outside the museum. An online petition calling for the removal of the works was also signed by more than 820,000 people. The museum left the areas where the works were supposed to be displayed empty for the duration of the exhibition. In place of Theater of the World , which would have featured hundreds of insects and reptiles in an enclosed octagonal space, the museum chose to display an empty cage. A museum spokesperson confirmed the acquisition of the piece, and said that it is considering the purchase of an Air France sickness bag, upon which Huang Yong Ping wrote, “An empty cage is not, by itself, reality. Reality is chaos inside calmness, violence under peace, and vice versa,” after learning that his work would not be fully exhibited.