Movie theaters are cracking down on cell phone use while movies are showing.

It's not just the annoyance of disturbing people trying to watch the film. The movie industry is also worried about piracy, especially now that smart phones have such high definition cameras.

The Motion Picture Association of America has updated the guidelines it gives theaters: it's encouraging managers to call the cops if they think someone is taping the movie.

Theater chains are trying to discourage the annoyance factor too.

Cinemark has released a smartphone app that offers rewards for movie watchers who silence their phones during showings.
--Rob Archer