[kintamanimatt]

It's not really a risk you can really protect against in any meaningful way with insurance. It's the banks that ultimately eat the loss, and they just write this off as a cost of doing business. Banks really do lose a lot of money to fraud, card losses, and other miscellaneous security issues and bad actors -- a lot more than people think.

Storing CC data can be done sufficiently securely, of course, although PCI DSS guidelines are insufficient and silly in places, and you really have to go above and beyond to make it secure enough because data breaches can threaten the status of your merchant account. If you become too costly or too risky to do business with, the bank will simply cut you off by terminating your merchant account. You may also end up on the TMF which will make it very hard to get another merchant facility in the future.