In the case of the Kaba Simplex, the magnetic field is able to move a critical component and allow the lock to be opened without the proper code.

FORBES: The Kaba Simplex lock is only for "access control": Is that what FDNY Engine Company 65 thought?

Today they can handle 80 times more information than the most advanced magnetic-stripe plastic, which usually contain little more than a name, an account number and a secret ID code.

CNN: ASIANOW - Asiaweek