Computer use in games can be a pretty contentious thing. The idea of having a laptop at the gaming table can be insulting, confusing or alien. It's a relatively recent argument as well, only really becoming an issue in the last decade or so since laptops and smartphones have become ubiquitous. Most people seem to have a pretty strong opinion one way or another, and they have good reason.

A lot of people will have nothing to do with laptops or computers at a game. They usually have some kind of "everything off" rule once game starts, or ask people to leave their computers at the door. I've seen storytellers confiscate smart phones to keep people from browsing Reddit when they aren't in the spotlight. At the opposite end of the spectrum we have people who won't game without the gadgets. These are the folks who integrate widgets, emulators and generators into their games, the kind of player that only has the books in PDF. By choice or necessity they depend on their computers to game. These are pretty extreme examples, but the divide exists, and when it gets crossed people can get very unhappy.

The arguments against bringing are pretty standard. People come to the table to be present in a RPG experience, and a laptop or smartphone represents an extremely tempting and convenient distraction from that experience. When you're front and center there's rarely a problem, but if you aren't in the limelight, it's very easy to find something just a little bit more interesting in the nigh-infinite stores of data that exist on the internet. Even without net access, computers have a laundry list of cheap, available entertainment. Games, music and movies all offer easy amusement when it isn't your turn or scene. This kind of drifting in and out of the game you all presumably came to play can easily be perceived as uncaring or insulting to the other players. Why would you bother to show up if you're going to spend the majority of the night browsing imgur? It's even worse if you're playing something with a GM: they (presumably) put effort and thought into every character, location and plot point that you ignore when you start sending off those emails you forgot about. There can even be games were every player is online. Someone GM'ing a GURPS game said it was like running five one-on-ones: each player was only really present when they were being directly addressed. For a lot of people those kinds of situations can just be too much.

Advocates have diverse, but no less valid arguments for integrating information technology into their games. The first big one is the idea of necessity. A lot of people who play these games are not in the best of financial situations, and E-books and PDFs come a lot cheaper than hardcover physical copies. If you need to repeatedly look things up, you're going to need your books pulled up and ready to go. If there's anything in those books you want to use repeatedly, or are having trouble remembering, same deal. There are people who almost never buy physical copies of games, who have grown up as gamers learning and playing from digital pages. In addition, some games couldn't be run without some kind of digital interface. Play-by-post forum games, skype games, and tabletop-simulators are all necessities for different kinds of long-distance games. Computers make playing with your friends on an opposite coast or another country possible, even easy to some extent. There are also those who simply enjoy the additions offered by computers in games. Groups use name generators, HP tracking apps and saveable character sheets to streamline and ease their playing experience. Sometimes they even make it a central part of their game. A one-shot exalted/wuxia hack used Seventh Sanctum's Martial Arts Move Generator for every attack or maneuver. A lot of people just enjoy or feel more comfortable with the things that are available when laptops abound: appropriate music on cue, searchable books and more are things that a lot of people just see no reason not to use.

Obviously not every group is going to stand at the extreme of this spectrum, with pencil and paper luddites at one end and the Borg at the other. It's usually pretty obvious when a computer needs to be put away, and even those most opposed to tech at the table will often play music off their desktop in the background.

Just having computers and phones available during game is not itself good or bad. There are valid reasons for and against, and each group of course needs to find its own balance of what it allows when. As with most things it comes down to individual players and DMs being responsible and not acting like dicks. There are horror stories, certainly, but good things can come of it if people are intelligent and mature. Tabletop gaming is quite a bit older than this technology, and we as a community are still getting used to having it available. It's just something we'll have to learn to integrate