As far as cyber-fraud goes, this is a biggie...

The online gaming credentials of 27 million South Koreans were obtained by cyber criminals, who then used these credentials to steal $400,000 worth of online currency, and make some more cash by on-selling details to various other lowlifes.

Police have arrested the apparent mastermind behind the operation...a 24 year old named Kim (that narrows it down), who enlisted the services of a Chinese hacker to pull off his dastardly plan.

Aside from the shear size of this theft, couple of mind boggling facts about all this..
  1. 27 million is over 70% of the entire South Korean adult population. Do any South Korean adults NOT play online games???
  2. This isn't the biggest cyber-theft that's occurred in South Korea. In 2011 the personal data of 35 million users of local social networks Nate and Cyworld was compromised.