Long ago I did some contract coding for a company that processed donations via credit card. To my amazement, we had to watch out for people trying to donate small amounts to the Red Cross. Why? Because people with a list of possibly-valid credit card numbers would use small donations to brand-name charities as a way of validating credit cards.

It made me long for some sort of professional association that kept track of naughty uses of technology. It's easy to think only about the happy path. But there are all sorts of unsavory people out there: abusers, mobsters, thieves, authoritarian governments. Once I know how they think, I can defend against them. But keeping up with how they think has always been a challenge for me.