I really hope that this improves the false-positive rate, as mentioned in another comment.<p>We've been hurt badly as a startup breaking into the US market and getting many of our genuine charges blocked by Radar (and at a "highest risk" level where it is not possible to disable rules).<p>As a developer, I had the best possible impression of Stripe, as they provide easily the cleanest API and best documentation of any payment provider I've used.<p>From a business side, it was highly frustrating losing so many of our early US sales. A lot of this was due to US banks blocking the payment, but Stripe did not handle these cases well in our case.<p>* Error messages presented to the customer are often ambiguous or misleading, and if you're using checkout.js you cannot customize these easily. In some cases, the customer gets a client-side "Card is declined" error, with no communication passed through to the merchant at all, which makes telephone support very difficult.<p>* Stripe will not provide any kind of telephone or chat support to merchants. By the time a specific blocked payment can be escalated to a "fraud specialist" the customer is usually long gone.<p>* Stripe will not allow you disable certain Radar rules.<p>* If a user tries to pay several times (due to their bank blocking the payment as suspicious), and then phones their bank to clear the payment, Stripe will often then block the payment due to "repeated attempted uses of the card". This is highly frustrating as even very determined customers who try several times and then contact their bank to resolve the issue there still get blocked by Stripe, and usually give up at that point.<p>* We had one payment blocked by Radar due to it being from a "high risk location" (Pakistan if I remember correctly). This represented unacceptable levels of discrimination for us. Machine learning and probability is useful, but ethically it's hugely problematic to deny people service based on their country, race, gender, age, or other attributes that they do not have control over.<p>My early experiences with PayPal were nothing short of terrible, but BrainTree is looking like a more and more attractive alternative to Stripe, especially with the PayPal integration built in -- if people have issues with their Credit Card they can simply pay with PayPal credit instead.