Originally Posted by Konda

Not sure what's going on. Netbilling uses Ezic for their backend and they are down too http://ezic.com/

They must have known it would take a long time because they wrote "Please make the necessary changes on your signup and checkout methods". The email came about 25 minutes after they went down.

Only thing I can think of is maybe there was a hack or critical system issue or PCI issue and they had to shut everything down?

https://netbilling.com works since it's not hosted on the Ezic network, but everything that is on Ezic like the api and backend is down. So it's not just Netbilling, but Ezic itself and all other Ezic clients are down as well.