Few weeks ago Ninteno officially announced that someone penetrated unauthorized access to their server. Nintendo is currently investigating the hack but it's safe to say that no data has been stolen.
A group of hackers, called LulzSec took the initiative to be responsible for Nintendo's hack on their Twitter page. LulzSec also mentioned that they had no intention of damaging the server and only copied the configuration file as a way to prove the hack. LulzSec just pointed out another hole inside Nintendo and suggests they fix it. Quoting LulzSec, "Nintendo is not our primary concern of attack, we truly want Nintendo to re-enforce their security".
The same group of hackers (LulzSec) hacked Sony PlayStation Network a while back except here they stole private client information, such as home address, emails, passwords, credit-cards, etc. Successfull attacks doesn't only bring company's reputation down but financial standing as well. According to AFP agency, after Sony's network hack their cost per share dropped to 2062 yen.