Can anyone share what they do regarding the $50 customer liability regarding Reg. E versus Visa's zero customer liability? Which one do you follow if your debit cards are Visa?

Your contract will require you to follow the $0 liability rule.

If it is a PIN transaction we follow the Reg E liability of $50 /$500 as PIN based transactions are not protected by zero liability, if it is a signature based transaction then we employ the zero liability.

Please note that the Visa Zero Liability Policy does not exclude all PIN transactions, just ATM and those not processed through the Visa network

1Covers U.S.-issued cards only. Does not apply to ATM transactions, PIN transactions not processed by Visa , or certain commercial card transactions. Individual provisional credit amounts are provided on a provisional basis and may be withheld, delayed, limited, or rescinded by your issuer based on factors such as gross negligence or fraud, delay in reporting unauthorized use, investigation and verification of claim and account standing and history. You must notify your financial institution immediately of any unauthorized use. Transaction at issue must be posted to your account before provisional credit may be issued. For specific restrictions, limitations and other details, please consult your issuer.

http://usa.visa.com/personal/security/visa_security_program/zero_liability.html