i read an article within the last year that talked about how the current generation of 20 and 30 somethings have completely fucked the manner and habits of todays restaurants.
for example, the average visit for these people has skyrocketed from say 45minutes-60minutes hypothetically (what it used to be on average from time of seating, ordering, eating and paying final bill) to say 80minutes - 120 minutes now because the vast majority of that demographic now does this because of smart phones.
arrive with party, wait to be seated, sit, receive menu, play with smart phone and share smart phone info (look at each others pictures, facebook, funny websites) send waiter away for first time because nobody has opened their menu to even look at items yet, waited returns (maybe twice), order, wait for food, food arrives, take pictures of food, share pictures of food and dining mates on social media (instagram, fb, twitter), take first bite of food, return food to be reheated because its cold and this is somehow the staffs fault, wait for food to return, eat while also playing with phone, finish eating, sit around and gab (this time is doubled because it takes twice as long because everyone is splitting time between phone and human interaction) pay bill, leave.
its not a bad rule that some establishments have made a hard "no phones at the table" rule. id be pissed as a waiter or chef.