families that actually pay income tax. the billionaires all keep their money in wealth accumulation and pay no taxes at all on it. that's just not right. >> reporter: i think it's important to really emphasize what you heard in that story, that this is legal, right? it is not against the law to work the tax system, but that is why you are seeing some in congress call for some changes moving forward. as for how these documents, this data itself was revealed in the first place, the treasury department is now referring an investigation into the unauthorized disclosure of what they call this confidential material to its inspector general, the fbi and the u.s. attorney for d.c. back to you. >> hallie jackson, our thanks to you. with us now is tax expert and pulitzer prize-winning reporter david cay johnson. thank you for being with us. you tell us in 55 years you have reported on taxes. this is the most important story by far.