Dave the Mobile Warrior pointed this out to me. While shopping, he noticed many workers whose jobs were to help and serve customers were engaged with activities contrary to what they were supposed to be doing on the job.
In one instance, he stood in line on from of a cashier for a while before she noticed him standing here. What was she doing? Texting.
I've noticed that as well. Think about this. If you're a receptionist who happens to be on the phone with a friend when a prospective customer comes up, you'll probably hang up and start doing your job.
It ought to be the same with texting, checking updates on Facebook, or tweeting (and e-mailing). However, it's a bit more difficult if the worker's head in lowered and concentrating on the phone.
It was funny when I heard about Dave the Mobile Warrior's experience. I'm sure there are far worst examples of bad mobile behaviors. Perhaps in time, we'll all adjust and learn from it.