A method and system for enabling personal digital assistants (PDAs) and protecting stored private data. Specifically, one embodiment in accordance with the present invention includes a removable expansion card about the size of a postage stamp which plugs into a slot of a personal digital assistant. The removable expansion card, referred to as a personality card, is capable of storing all of a user's private information and data which is used within their personal digital assistant. By removing the personality card from the personal digital assistant, all of the user's private information and data may be removed from the personal digital assistant. Furthermore, the personal digital assistant may also be rendered totally or partially useless once the personality card is removed from it. There are several advantages associated with a personality card system in accordance with the present invention. For example, one of the advantages is that a user is able to restrict access to their stored private information and data by simply removing their personality card from their personal digital assistant. Furthermore, as personal digital assistants equipped with personality card slots become increasingly more common, a user will be able to continually carry around their personality card and enable a spare and locally available personal digital assistant with their private information when desired.