So I read the recent post by Yoshi-P and his explanation about the emergency maintenance concerning the market fraud, and this idea immediately popped into my head. In a show called Ghost in the Shell, there is an episode where this rebel is stealing a fraction of one cent from everyone (in the world?) from every transaction that they make. Since there are billions (trillions?) of people, this guy is making a fortune, and fast.
From what little information that is given in the update post, what with the security factor and all, this is what I think might be the cause of the maintenance; gold farmers gaining a percentage of some of the more costly items on the market boards.

What do you think?