I recently saw a preview of a Pixar movie before the public release, and their solution was to make us put our phones in an extremely crinkly bag that would mak

I recently saw a preview of a Pixar movie before the public release, and their solution was to make us put our phones in an extremely crinkly bag that would make noise if we tried to open it to surreptitiously video the screen. But we could still access them in an emergency. It wouldn't work at a loud concert, of course.