[Raidion]

Every SaaS platform with a reasonably cheap offering deals with these. I work for a recognizable SaaS and there are checks that flag both the accounts and reports the credit cards that are used after a fairly low threshold of "add payment method attempts". High levels of fraud usage hurt your reputation with payment processors and that's bad for business.

It doesn't stop the truly determined ones I'm sure, but it does mean that it adds complexity. You don't need to be impossible to test cards on, you just need to be harder to use than someone else (like a lower resource charity). We've even debated "fake accepting" some payment methods after we're confident it's someone trying to find working credit card numbers to add some false positives into the mix.