The Con Side
Smart cards are small and light, which makes them conveneintly portable, but it also makes them susceptible to loss and theft. If a card is mishandled or misplaced, the technologies that provide security and convenience can instantly become a source of vulnerability and expense. In the case of building access, for example, if a card is lost and not reported, it can increase the chances of a security breach.
A far greater issue, however is privacy. Leaving a trail of digital tracks using separate cards for distinct purposes is of little consequence to the majority of people in most cases. A person may use one type of card to access public transportation, a key card to enter a building, a credit card for purchases, another for network authentication, and a health insurance identification card with access to electronic medical records.
For privacy advocates, the big problem begins with the idea of compiling all of an individual's personal records into one central database and using a single, universal smart card for all electronic transactions that require authentication. Consider the immigration reform proposal, which calls for the creation of a biometric, mandatory national ID card. Although it is intended not to include any personal information, a national ID smart card, in the wake of the Real ID Act of 2005, would set a precedent that privacy organizations, such as the American Civil Liberties Union (ACLU), are staunchly against.