Question: No doubt you’ve read plenty about con artists stealing Social Security numbers (SSNs) to obtain fraudulent credit cards. And, unfortunately, your HR personnel files are a goldmine for ID thieves, filled with all kinds of juicy personal data.

But a new court ruling shows that the rise in identity theft doesn’t excuse employees from disclosing their SSNs to employers. You can and must insist on getting this data for I-9, background-check and tax-reporting reasons. And you needn’t fear a lawsuit if you refuse to hire (or later fire) new employees who fail to provide the information.

Case in Point: When John McCauley was hired for a computer help-desk job, HR asked him to fill out several employment forms. He left the section blank that asked for his SSN. He also asked the recruiting manager whether he could skip providing the number on his I-9 form. McCauley was apparently concerned that turning over his SSN might make him more susceptible to identity theft.

The company fired him for not meeting the hiring criteria. He sued, alleging he had been discriminated against because of his nationality (American) and that providing the SSN was a violation of his right to privacy. He argued that foreign employees who come to work with a visa don’t have to supply a Social Security number.

The 3rd Circuit Court of Appeals tossed out his case, noting that “federal law requires employers to collect Social Security numbers to aid enforcement of tax and immigration laws, and that these requirements apply to all employees.” Plus, the court said that, “Requiring disclosure of a Social Security number does not so threaten the sanctity of individual privacy as to require constitutional protection.” (McCauley v. Salvaggio, et al., No. 06-4089, 3rd Cir., 2007)

What does this new case mean to you?