So one of the things in Piketty's Capital that none of the pundits picked up on was the observation that between 40 and 70% of the wealth in the world is unreported, hidden in offshore accounts... and that one aspect of the USA PATRIOT Act that gets very little play is it beefed the fuck out of the Bank Secrecy Act such that the USA has the most viciously stringent investigation and seizure instruments in the world. He even argued that one of the reasons for the past decade of US prosperity was the fact that the US treasury department actually had the instruments and reach necessary to force compliance with its foreign disclosure requirements, radically increasing the amount of taxes the US was able to collect on monies held in foreign accounts. 2.6 TB of "here's where the money is" might be of interest to the Treasury Department.
From the numbers I've seen, if we seized all that money, it would pay off the entire national debt and a third more ($20 trillion illegal money, $15 trillion debt). Of course, I'm not sure if it's legal to seize all the money, or just the unpaid taxes. My instinct is that it's legal to at least freeze it all. Also, who would have guessed I'd one day be cheering for the PATRIOT Act?
The people whose monies have ever made a loop through the US financial system are likely to find any of their funds within the US or its banking agreement signatories seized. Not all of them, but enough to cover the taxes that are being sheltered. Having looked over the list, most of the people getting busted are the ones that don't have any money going through the US precisely because of the Bank Secrecy Act. It'll be interesting to see how it shakes out. Because there are so many countries involved, and because everyone is going to have their own spin on it, I don't really know how it's going to matter... I'm actually not optimistic that much will change, but I imagine attempts to loosen US banking laws are not going to go through as easily.