Next time someone complains about your habit of using a cellphone in the movie theater, just casually tell him this story of a man who got stabbed with a meat thermometer after making a similar complaint.
It was 9:00 PM on a Saturday night and people were watching Shutter Island in a Lancaster movie theater when a man started whining that a woman seated near him was talking on her cellphone. He thought his concerns were well-received when he noticed the woman and her two fellows get up and leave. The next thing he knew though, he had a meat thermometer sticking out of his neck, courtesy of one of the men.
The complainer has been hospitalized and the stabber has not been caught. So be careful about what you say in a movie theater.