Worldwide, 56 participants were arrested, according to an FBI statement.
What makes the story so scary is the straightforward, businesslike approach the crooks took to setting up and running their online exchange: membership was by invitation only, and there was evidently a strong social networking as well as buying and selling of stolen data aspect to the undertaking.
We've been seeing -- and saying! -- for some time that cybercrime is functioning more and more as a structured economy, following business and organizational rules.
Maybe the silver lining is that that sort of operation will prove less difficult to infiltrate and bring down.