The dark gray device used to detect cell phones looks like an oversized walkie-talkie. When Scott Schober, president of a Metuchen technology company, flipped it on in an officer cafeteria at a New Jersey jail several months ago, a warning immediately flashed. “I turned around and walked out and said, ‘You’ve got phones in there,”‘ he said, describing the demonstration he gave for officials. “They basically said, ‘We’re not surprised.”‘ Cell phones are illegal in […]