Learn from the big mistakes of cashless payment service in Japan

The Japanese cashless payment service industry has experienced four major fraudulent withdrawals. I will explain three of them. Based on the major mistakes made by Japan's leading companies, 7-Eleven, Docomo (Japan's largest cell phone), and Japan Post Bank (Japan's fourth largest bank and a former state-owned company), I’ll explore the deeper causes that led to these incidents. In all three cases, two major mistakes were made; if they had been dealt with properly the first time, less damage would have been done.
The payment systems in Taiwan and Japan are very similar, so there should be great lessons to be learned.