Here is the link to the FBI’s website so you can see for yourself what they have to say about the legality of CPN’s. The sections that states CPN’s are legal is section 35 found close to the bottom of the page. We have also cut and pasted that section under the link.
35. Credit Privacy Numbers (CPNs) are nine-digit file numbers that follow the same algorithm as Social Security Account Numbers (SSANs). Currently, federal law allows individuals to legally use CPNs for financial reporting and protects those individuals who do not wish to disclose their SSAN. Individuals who acquire CPNs are completely responsible for any debt they incur using this number. Acquiring a CPN is supposed to be a free service; therefore, Web sites that offer CPNs for a fee are most likely scammers.