> I've been doing this for 10 years now, and as soon as someone opens up a payment system like this, money laundering and other schemes will review how to abuse it. So when I see something like this, I get nervous. I ask: how would I exploit it.

Maybe you should write a guide of all the ways you've seen people go wrong and the best ways to do things (and why). That could be useful to a lot of people on HN.