When you play WGT, be sure to log in using your own account. Our terms of service allows each player to have just one account, and to only play the game using your own account. By sharing an account with someone else, or playing games using another person's account, you run a risk of having the accounts blocked. You also run the risk of being disqualified from any tournaments you played.
Speaking of the terms of service, be sure to check them out from time to time as they change periodically.