Do we have any kind of case for being banned from an online game for receiving items acquired fraudulently from another user?

Theft and the sale/transfer of stolen items via the Internet is a growing problem. If the game is owned privately, the owner can do as he or she wishes. However, the problem is not your girlfriend receiving stolen goods (assuming she didn't know they were stolen), it's that someone stole the goods to begin with. If a player cannot refuse a gift according to the rules of the game, your girlfriend is only obligated to return the stolen items to the game owner. But the game owner should be going after the thief and seeking recovery from him/her. If the game owner won't discuss this issue with you, contact an attorney to explain the law to him/her.

Your girlfriend should go to the game and look on the site and try to get in contact with a supervisor or manager. She should tell them just what you told me. She should say she thought the gifts were legitimate, she had no way of knowing they were not, she had no way to reject the gifts, and she has been a good player for years and wants to continue to play. She should pursue talking to other people. If that does not work, she should contact the legal department of the game company and explain the same things. However, if the game company has evidence that your girlfriend was colluding with the other to somehow steal the gifts, then they do have a right to ban her. It is hard for game players to realize that games are just games and by playing the game, you are usually giving the game company the right to make decisions.