Increase: Banking API
I made an API for a bank...   I was a third party and made the API by screen scraping their webUI.   I sent their devs a link and initially there were positive messages going back and forth.<p>The API allowed you to see balance, transaction history, and make payments.<p>Before long, the API got quite popular, and lots of people were using it to make lots of payments automatically.<p>You know what makes money laundering super easy...   a banking API so you can split the million dollars you want to launder into 1 million 1 dollar payments.   And an API client which lets you treat each login cookie and account as an object in python.<p>Before long, the API and all users who had ever used it were perma-banned from the bank, because it was determined they posed too high a fraud/money-laundering risk.<p>I'm still salty because, after spending a week of my life building and refining that API, they banned me and <i>6 years later</i> still claim they can't return the $350 that was in the account because they are still 'investigating'.