We think they're intruding on us.

From "Recently I heard a woman say her department is full of freaks, they don’t like her, and she doesn’t have a life, but that sounded more like a whine than an epiphany." by Ann Althouse.

She can be kind of circuitous sometimes but she often has interesting insights about how and what we communicate.

Did people become less self-conscious because of cellphones? It's very hard to compare what you're hearing now with what you heard back then. Stan Mack is kind of an authority on the subject, and the difference he cites is in the interestingness. If what people are saying these days is less interesting, it could be that people are more private, less prone to revealing themselves when they can be overheard. But it could be that the eavesdropper has changed, and not just because we've all gotten older. We're different because we're listening to phone talkers, not to people who are with other people and talking in the flesh. People talking into a phone irritate us a lot more, so we're more judgmental. We think they're intruding on us. When we listen to people who are together in real life — as in "Real Life Funnies" — we feel that we are intruding on them. Our transgression makes things inherently more interesting.