I was a bystander in more than one. Most of those were at the Folsom Street Fair where I happened to be in the crowd when they were filming. But I was also on their digital email list, and they would occasionally send out emails inviting folks to attend. You had to have a valid ID, couldn't be drunk or on drugs, and had to sign a consent form. The guys in the crowd who interacted with the performers were paid porn performers, but most of the rest were unpaid extras Who weren’t allowed to interact too directly with the models unless invited to do so. I only went to a few where the guests were invited to wear masquerade masks, and I attempted to avoid being in view of the camera. We were allowed to take cell phone photos but not other digital cameras. I might be to blame for that; before that policy, I brought a pocket digital camera and took hundreds of photos. This was before iPhone photos were as good or better than many digital cameras. I also went to one of the NakedKombat wrestling shoots that had a live audience.