I went to a show at Fabric in London during Kubecon last spring and they did the same thing. I still saw the odd person who peeled it off taking selfies or pics of friends inside but that was definitely the exception.
Perhaps it can be enforced with a type of laser that doesn’t damage the human eye but completely obliterates a phone camera. As long as you keep the sticker on nothing happens to your phone.
Perhaps it can be enforced with a type of laser that doesn’t damage the human eye but completely obliterates a phone camera. As long as you keep the sticker on nothing happens to your phone.