An official statement on the site (in Japanese) explains So-Net has terminated exchanges of points, and asked customers to change their passwords. The story translator says the total lost was "about 100,000 yen," or $1,224. Google's translation of the site reads that as "approximately 10 million yen," or $122,384, which is probably why we shouldn't trust Google Translate.
And it was Brute Forced!!
Link to Original Source