Because it's against the law to reveal that information. IRS and SS are forbidden to give that information to ANYBODY.
ummm....You mean it ain't fraud? I'm just guesing here, but I suspect that both the IRS and SSA both have investigative and enforcement arms that are tasked with exactly that purpose in mind...else we would all be using bogus numbers and skip merrily away from any prosecution.
"Because it's against the law to reveal that information. IRS and SS are forbidden to give that information to ANYBODY"
It may be true that the IRS and SSA are forbidden to give that information to anybody ELSE, but they do share information between their two agencies, and crosscheck tax returns with valid SS numbers.
This is complete BS. There is no prohibition for one government agency passing private information to another government agency for legitimate law enforcement purposes. Ask Al Capone. Oh yeah, I forgot. He died in prison of syphilis. They got him on tax evasion charges. I wonder how the prosecutors got their hands on his private tax information.