Friends account banned for no reason

My friends account has been given a 72 hour ban for "Reason for Action: Terms of Use Violation -- Exploitative Activity: Abuse of the Economy" for no reason. This has happened to him before simply because he enjoys to make gold and has somewhere around 200k and moves alot of it around between his characters and buys expensive items as he is collecting pets/mounts.

The account is [Removed]

It is pretty unfair to be banned simply for using the auction house to make gold which is the reason it is in the game. The ban was probably automated(most likely to stop gold sellers) but banning a player that has been paying for this game for 4 years and using the features as they are intended is just wrong. :S