This feels like a business model where the lean/MVP approach isn't quite appropriate. A lot of things fall out of that decision, not the least of which is that

This feels like a business model where the lean/MVP approach isn't quite appropriate. A lot of things fall out of that decision, not the least of which is that the exposure surface area you get from an environment that allows user-sourced code on purpose is enormous. I feel for the guys going through this but there were a lot of errors in the wild all at once to allow this to happen.