A lot of great articles can be written about all kind of spectacular things that almost were done...Anyway nice article on Klarna and their security way of thinking...not groundbreaking as you can read
Swedish payments startup Klarna once considered a novel approach to dealing with fraud: Asking "high-risk" customers to enter their horoscopes. The company, which was valued at $2.25 billion (£1.5 billion) in a 2015 funding round, offers a payment solution to merchants that tries to simplify paying online. Where it differs from PayPal, or a website's proprietary payment method is that customers don't need to even enter their card details when they pay. They stick in their email address and postcode — and that's it. Klarna goes ahead and pays the the merchant, and the customer then pays Klarna at a later date. The goal is to increase "conversions" — the number of people going through with payment — by removing hurdles and streamlining the process. But by fronting up its own money, Klarna puts itself at obvious risk of fraud.