If I may, I will answer that question. Currently, the Internal Revenue Service has a program called “Streamlined”, to allow non-compliant U.S. citizens to come into compliance. What they are requiring as part of that is six years of foreign bank account reports, known as FBARs, sent directly to the IRS.
Now normally, these are sent to the U.S. Treasury, and the IRS wouldn't see them. The reason the IRS wants them is that they are absolutely the best indicator they have about a person's financial status and whether they meet the test of what the IRS would call “low compliance risk”. There's absolutely no question that this information tells one far more about somebody's finances than anything else.