NY Times article

To answer the question why... I think there is more of a connection physically when you have a human being standing in front of you as the artwork. There is more of a human urge to naturally touch and have the sense of connection. I think we are accustom to understanding that when you walk into a museum or gallery you do not touch artwork, but when the artwork is a person the rules don't seem to apply the same way to some people. When an artist is expressing their work physically, I think certain people are overcome and use that as an open door to be able to take advantage of the expression.