Kanajun, many OTB tournaments, especially National ones, have players turn their cellphones off.
In the Nationals (United States), a player cannot talk to anyone outside of the
playing room except for the Tournament Director and your opponent (offering a draw).
Yeah, some people do cheat, and people cheat on chess.com too.
Played against someone who beat me 4 straight games and every game they played flawless. I reported them and sure enough they were. I still don't know how they can say for sure but they use a system that decides. You can report cheating, but be pretty sure they are, like more than 1 game. I lose games all the time where it seems like they "know" what you are going to do. A lot of times you fall into these situations and it seems like they might be cheating. I think Chess.com needs several games to study to decide.
If you suspect someone of cheating, please use the top corner Help link. When that page opens, click on the left side option where it says Contact Us and submit a 'Suspected Cheat' ticket.
Also see this page
http://www.chess.com/forum/view/community/chesscom-policy-on-cheating
We provide tools to report cheating to our staff. But having several constant and redundant threads on the topic that circulate with the same questions and comments over and over again isn't helpful, and instead causes people to worry more than they need to. If you want to discuss cheating, please do it in this group
http://www.chess.com/groups/home/cheating-forum
Im kind of a rookie on Chess.com and i suspect that there is more motivation to cheat in tournaments than in non-rated games ... how do they get away with it, how do they get caught and do tournament organisers self regulate.
Discussion of chess.com cheating is restricted to
http://www.chess.com/groups/forum/cheating-forum
Mod.