Even storing complete cards numbers is only allowed under very specific conditions. We encrypt these at the app, even before putting them into the DB, yada yad

Even storing complete cards numbers is only allowed under very specific conditions. We encrypt these at the app, even before putting them into the DB, yada yada. The PCI auditor actually made us restore the DB from backup onto another server and show them the data, to prove that some magical process in the backup program didn't cause them to come un-encrypted. They also wanted us to change all corporate email addresses to random characters, ostensibly to prevent spearfishing (we declined to take this suggestion). My point is that they go to crazy lengths to ensure you're doing this stuff right.