The one that was most controversial was the 2003 documented video called "Dogs That Cannot Touch Each Other," which showed two dogs facing each other but couldn't touch because they were chained to non-motorized treadmills. The staging of the work was created by Sun Yan and Peng Yu. The animals were clearly frustrated and exhausted. Not long after, a petition was launched that received over 420,000 signatures voting against the animal exhibition video.
Stephanie Lewis, an author for the petition commented 'Animal cruelty is not art in the United States or anywhere in the world'. The Guggenheim Museum pledged to defend the work of Sun Yan and Peng Yu by stating: 'This work, which can be disturbing, and deliberately provocative, seeks to examine and criticize systems of power and control'. Two other works are strongly criticized by animal rights activist. The first is a video where we see pigs tattooed by artist Xu Bing. On the second, it shows an arena where hundreds of insects and reptiles confront each other and devour each other.