There is a very interesting documentary about a couple of his shoots in NYC--one in Times Square, the other at a gas station--at the time, he didn't have permits, so it had to be staged as a sort of guerilla project--move in, block the streets, subjects stripped, layed out in the streets, with Tunick directing and trying to shoot and get people out before the cops arrived--
The images of hundreds of nude bodies, lying in an otherwise empty Times Square are definately disturbing--holocaust-like-