That was damn informative Unclebob. While both sides were idiotic, Nintendo bear the greater responsibility for such a ridiculous breach in security given the amount of trust placed. Through incompetence or embarrassment, who ever received the e-mail over at Nintendo dealt with it poorly by trying to sweep it under the rug. The rubbish e-mail sent to Nintendo didn't help matters, along with the dude's decision to go on-line to debate the moral implications.
He had 5 options.
1. Do nothing. Effectively removes most of the liability on his part assuming he literally does nothing and holds none of the data. Nintendo and the users people run the risk of massive damage from someone far more unscrupulous and competent.
2. Go straight to the authorities. Given the the size of Nintendo, it would no doubt cause a scandal. Most damaging to Nintendo. Users get protected. Dude walks.
3. Talk to Nintendo without implying potential reward/blackmail. Had the potential for the best outcome for all involved. Nintendo get to fix the issue quietly. Dude gets tossed a 3DS on launch and/or clear conscience. Requires competence on both sides.
4. Blackmail Nintendo for real.
5. Sell the info.
He chose option 6 which is option 3 with everybody falling over each other to **** up the most. Dude goes to court. Nintendo gets a scandal and real hackers of lesser scruples are no doubt having a real go at them now. Heads roll.