“Modify that provision of the IRS code.”
I’m curious, is this in IRS code passed by Congress, or is this in IRS made code? If the former, get Congress in session until they fix this problem; if the latter, just make the commissioner change the IRS code under threat of prison if he doesn’t.
Your almost to the right question: If we, the citizens, are handed a circular butt-covering load of excuses as to why one agency can not give another one information that is necessary for proper and duly passed law enforcement shouldn't we citizens conduct our affairs along the same lines?
Seriously though, many posters have noted the President, Congress, heads of the respective IRS and Social Security Administration, the Supreme Court and ultimately US possess the power to make these agencies cough it up and provide this information to the FBI (note I omitted Homeland Security - too rife with corruption and agendas). No agency has immunity from the citizens they supposedly serve except those handling critical national security information. The last I heard the SSA and the IRS are not remotely dealing with business that's in the CIA and NSA domain.