If I wanted to stop movies from being pirated, I'd focus my effort on the places where they leak. In the case of the Oscars, that's the insider awards voters who leak every movie they're sent within six days, not the film critics - who have never, ever leaked a movie by recording it at a preview.Stop worrying, Hollywood - nobody is stealing your films with mobiles
Likewise, if I wanted to secure hundreds of mobile phones, my first resort would be to leave them where they are, in cinemagoers' pockets, which is surely the safest place for them to be. Failing that, I'd have a top-notch security system, with tamper-evident, shielded, opaque bags for storing phones, a system of multiple watchers who kept an eye on each other as well as the phones, and special background checks into anyone allowed anywhere in the vicinity of the handsets.
Oh, and I'd make sure I was carrying special insurance that specifically covered losses due to data breaches from phones in my care.
What does the film industry do to safeguard your phone when you see a preview? It's very hard to say. No one could really tell me what the details were.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.