Why I Blasted Your “Drug” Deals on Twitter

How it happened

A couple of days ago Twitter user Mike Rundle tweeted a link for the endpoint to Venmo’s public API. I learned that Venmo’s public by default setting made the details of millions of Venmo transactions publicly available to anyone who cared to look. So I did what any software engineer would do and started digging through the data. I could see the names, Facebook profile pictures, payment types and “message” fields that users filled out when they made a transaction.