In 2000, there was an exhibition called ‘Helena’ created by Marco Evaristti. This exhibition put ten functioning blenders on the table, and each blender containing a live goldfish. The blenders were plugged in and if anyone press the yellow button, the goldfish will die. Therefore, people will decide the lives and deaths of these goldfish. The creator was charged with animal cruelty. But he appealed against it. After a long period of confirmation by the expert witnesses, they state that kill goldfish within one second was one of the more humane methods. Therefore, the creator was acquittal. This exhibition has aroused unprecedented controversy and the use of animals in contemporary art.