Cell Phones as Props

When visiting my parents in New York City this month, my mother said she thought some people use their cell phones as a prop to avoid having to talk or otherwise interact with the other people around them. She said she has heard some of these alleged "conversations" and she decided they couldn't possibly be real telephone calls, because what the people are saying is so inane and nonsensical. (She's not up on the young people lingo, apparently.) But I think that in NYC, their use as props is for a different reason. Clearly, I'd say that everyone is just crazy, and they're using their cell phones to cover for the fact that they're talking to unseen voices in their heads, or else they're talking to themselves, or to imaginary friends, and they're tired of always getting sent to Bellevue's psychopathic ward.