I observed a significant security flaw in Modernbill. Client account passwords are available to admin users in plain-text. This means that a disgruntled employee can collect passwords from all accounts and engage in a wide range of fraud activities. This also means that, considering that many people use the same passwords repeatedly, people using modern-bill based systems are vulnerable to being victims of fraud in other ecommerce accounts as well.

darn... have you emailed them? They can probably have this fixed asap.