The invention provides systems and methods for protecting information related to credit card accounts and other kinds of information displayed on personal and identification cards. In some embodiments, the invention further provides a credit card with a card portion displaying a first part of an account number and an electronically readable region. The credit card may also include a sleeve portion that holds the card portion and that may display a second part of an account number. The sleeve portion may have a window through which the first part of the account number is visible, so that the first and second parts of the account number provide a complete valid account number.