I guess that "optional" line for a SSN on a Form 4473 isn't going into a database somewhere, right? 
FBI getting Social Security data
By Eric Lichtblau The New York Times
http://www.iht.com/articles/2005/06/22/news/social.php#
WEDNESDAY, JUNE 22, 2005
WASHINGTON The Social Security Administration has relaxed its privacy restrictions and turned over information on thousands of people to the FBI as part of terrorism investigations since the Sept. 11 attacks, newly disclosed records and interviews show.
While the agency, whose main role is running the nationally financed retirement system, typically bans the disclosure of such sensitive information, officials began providing the information just days after the attacks to help the FBI get data on the hijackers, possible terrorists and even victims of the attack. The disclosures came in agency documents that were obtained by a private group through a freedom-of-information request and provided to The New York Times.
Social Security officials, in policy memos beginning on Sept. 13, 2001, and updated through last year, authorized a policy allowing the FBI to gain access in some cases to the documents, including earnings and employer information.
In the past, the agency had insisted on privacy standards that went beyond U.S. law, disclosing information to law enforcement officials only for someone who had been indicted. Under the eased rules, the agency also shared information in at least one other major investigation - the 2002 investigation of the sniper attacks in the Washington area, the documents show.
"We ran thousands of Social Security numbers," said a former senior official at the FBI who spoke on condition of anonymity. "We got very useful information, that's for sure. We recognized the value of having that information to track leads and, to their credit, so did the Social Security Administration."
But some privacy advocates and members of Congress, while sympathetic to the extraordinary demands posed by the Sept. 11 investigation, said they were troubled that the Social Security Administration abruptly shifted policy with no public discussion.
"We in Congress were never told about this," said Representative Carolyn Maloney, Democrat of New York. She added, "This process has real civil liberties implications for abuse."
FBI getting Social Security data
By Eric Lichtblau The New York Times
http://www.iht.com/articles/2005/06/22/news/social.php#
WEDNESDAY, JUNE 22, 2005
WASHINGTON The Social Security Administration has relaxed its privacy restrictions and turned over information on thousands of people to the FBI as part of terrorism investigations since the Sept. 11 attacks, newly disclosed records and interviews show.
While the agency, whose main role is running the nationally financed retirement system, typically bans the disclosure of such sensitive information, officials began providing the information just days after the attacks to help the FBI get data on the hijackers, possible terrorists and even victims of the attack. The disclosures came in agency documents that were obtained by a private group through a freedom-of-information request and provided to The New York Times.
Social Security officials, in policy memos beginning on Sept. 13, 2001, and updated through last year, authorized a policy allowing the FBI to gain access in some cases to the documents, including earnings and employer information.
In the past, the agency had insisted on privacy standards that went beyond U.S. law, disclosing information to law enforcement officials only for someone who had been indicted. Under the eased rules, the agency also shared information in at least one other major investigation - the 2002 investigation of the sniper attacks in the Washington area, the documents show.
"We ran thousands of Social Security numbers," said a former senior official at the FBI who spoke on condition of anonymity. "We got very useful information, that's for sure. We recognized the value of having that information to track leads and, to their credit, so did the Social Security Administration."
But some privacy advocates and members of Congress, while sympathetic to the extraordinary demands posed by the Sept. 11 investigation, said they were troubled that the Social Security Administration abruptly shifted policy with no public discussion.
"We in Congress were never told about this," said Representative Carolyn Maloney, Democrat of New York. She added, "This process has real civil liberties implications for abuse."