just a single move or advice by another player in a crucial moment could  change the outcome of the game and of an entire tournament. therefore it may have destroyed a whole tournament. you may have lost a game if not for your Gm friend and may have changed the outcome of a tournament. 

shadowknight sorry to hear that. scorpion is not my coach, just my friend. you can open another account at icc

the GM was not helping me, he was just playing on this site to see how strong the players were and could not find a higher player than his last game so we left. 

Under whose name? Geez, you both should know better. If he's interested in the play here, he can create his own account in about 1 minute.

Blatant cheating & inexcusable towards your opponents. You should be ashamed of yourself...

a word of advice: if you want to stay anonymous don't use the same profile picture when you make a new account (I know who you are)

On topic: the reason it's cheating to let a GM use your account is, imagine a GM uses your account, then they are unfairly taking rating points off everyone they beat as your rating is far lower than the GM's. then if you play rated games everyone else gets easy points. Thats why only one person should use an account.

      If you let someone else play your game as you, then it's cheating in my opinion. I play as "birdmove". If Yasser Seirawan came over to my house and asked to play some games using my birdmove account, then that would be cheating . It's not fair to opponents who believe they are playing me. It's not fair to use a computer to help you decide on moves. You and only you should decide what moves to make, or else why are we doing this at all?

    Jon

another problem by letting a grandmaster try tactics trainer in your  2000 rated account.
tactic trainer excercises are based on the rating of the people solving the excercises and if a GM is trying a Tactic he will easily solve a tactic and afterwards tactic trainer will assume that 2000 rated players can easily solve it. 

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