6 C.F.R. § 5.33 Use and collection of social security numbers.
Title 6 - Homeland Security
Each component shall ensure that employees authorized to collect information are aware: (a) That individuals may not be denied any right, benefit, or privilege as a result of refusing to provide their social security numbers, unless the collection is authorized either by a statute or by a regulation issued prior to 1975; and (b) That individuals requested to provide their social security numbers must be informed of: (1) Whether providing social security numbers is mandatory or voluntary; (2) Any statutory or regulatory authority that authorizes the collection of social security numbers; and (3) The uses that will be made of the numbers.
Title 6: Homeland Security
PART 5—DISCLOSURE OF RECORDS AND INFORMATION
Subpart B—Privacy Act
§ 5.33 Use and collection of social security numbers.

