Social Security Number Non-Proliferation Act of 2007 - Amends title II (Old Age, Survivors and Disability Insurance) (OASDI) of the Social Security Act to prohibit the sale, purchase, and display to the general public of an individual's Social Security account number without the individual's voluntary and written consent, with certain law enforcement, national security, public health, and other exceptions.
Makes it unlawful, also, to obtain or use any individual's Social Security number for the purpose of: (1) locating or identifying the individual with the intent to physically injure or harm him or her; or (2) using the individual's identity for any illegal purpose.
Makes it unlawful for any person to communicate to any agency or instrumentality of the United States or of any state or local government the Social Security account number of an individual, other than his or her own, without the individual's written permission, unless the number was requested by the agency or instrumentality.
Prohibits displays of Social Security account numbers on cards or tags required for access to goods, services, or benefits, and displays on employee identification cards or tags.
Prescribes criminal penalties for violations of this Act.