Article here: http://www.artlurker.com/2009/09/the-rape-tunnel-by-sheila-zareno/

Here's his idea, from the article: "In the 4D Gallery main room, I’ve constructed a 22 ft tunnel out of plywood that leads into the project room. There is no way in or out of the project room except for this tunnel. As you travel through the tunnel, it gets smaller and smaller, making it so that you have to crawl and put yourself in a submissive position in order to reach the tunnel’s destination. At the end of the tunnel the subject will find me waiting in the project room and I’ll try to the best of my ability to overpower and rape the person who crawls through."

When asked "Why rape?" he answers, "Because as an artistic gesture, it’s one of the most impactful I can think of."