Stripe has fraud prevention built in. How is their service deficient? Also, it sounds like these rules need to manually be set up, rather than having an out-of

Stripe has fraud prevention built in. How is their service deficient? Also, it sounds like these rules need to manually be set up, rather than having an out-of-the-box system that just works. Is this right? Do us merchants need to understand fraud patterns to make use out of this? Finally, aside from the geo ip which may require an API call, what's stopping someone writing a free library that does the same thing? What's your differentiator?