I had a sort-of related experience with PayPal where the machine said "No." I've been using it for at least 10 years at that point. What I did was try to pay for some cheap VPS hosting in Italy. The transaction was denied. I thought there was some problem with my CC, so I immediately tried to do a $1 transaction with some other company and it went without a hitch. So I contacted PayPal support about it and the next d…
> and for security reasons we're unable to offer further details To give a little behind-the-scenes here, I worked for a bit for a web hosting company that had this as standard policy. This was because, before it was put in place, scammers would actually use coordinated campaigns of support calls with otherwise legitimate accounts in order to extract piecemeal details about how the company's fraud investigations work…
> The hackers explained that they were able to breach the banks’ sub-par security by using an algorithm to generate account numbers and then posing as customers who had forgotten their passwords.
“They were giving too much permission to half-authenticated account which enabled us to grab all these information,” the email said, adding that the system “was not checking if a password was valid until the security question were input correctly.”
Source: https://www.ccn.com/hackers-demand-1-million-in-xrp-after-br...